Reinhart Poprawe, LIA’s 2012 president, has worked in the laser industry and its related organizations for over 30 years. He received an M.A. in physics from California State University in Fresno in 1977. After completion of his Ph.D. in physics (Darmstadt, 1984) he joined the Fraunhofer Institute for Laser Technology in Aachen, Germany where he worked as head of a department for laser-oriented process development.

In 1988 Poprawe started Thyssen Laser Technik GMBH and was the company’s CEO. Since 1996 he has been managing director of the Fraunhofer Institute for Laser Technology and holds the University Chair for Laser Technology at the RWTH Aachen. In 2004 he served as vice rector of Aachen University and currently is a member of several boards in the scientific and industrial organizations, e.g. the AKL Arbeitskreis Lasertechnik e. V. Aachen. He also chairs the RWTH International Board and is the Rectors delegate for China.

Poprawe’s main areas of expertise are laser applications, laser additive manufacturing, rapid prototyping, micro technology and photonics in life science. He also has vast experience in laser development and with plasma technology in the realms of process analysis, sensors for laser processes, laser induced plasmas, EUV sources for lithography and microscopy, XUV-sources and laser induced breakdown spectroscopy.

ILT is the leading laser center in Europe. The aim of ILT activities is the economical application of lasers in the industry. The services offered by ILT include strategic research, applied research on products and processes, prototype development, quality management, consultancy and training programs. ILT has spun out 30 companies with a total of about 1.000 employees in the past with the annual rate being a little over one company per year.
During His Term

Poprawe has been an LIA board member since 2001, editor-in-chief of the Journal of Laser Applications^® (JLA) since 2010 and was the 2011 president-elect. In 2006 he became a fellow of the LIA. During his term as LIA 2012 president, Poprawe would like to accomplish the following goals: see more attendees at all of LIA’s conferences, courses and workshops, which shall help increase the society’s bottom line and see LIA’s reputation and message of laser safety gain momentum in the form of more members. Additionally, he will be working to make LIA’s 30-year-old International Congress on Applications of Lasers & Electro-Optics (ICALEO^®) the number one global laser conference with top quality invited speakers, first class and relevant presentations and top notch infrastructure and events. Emphasis will also be put on making JLA the top global journal in laser applications.

Poprawe will be kept busier than most LIA presidents as during 2012 another topical workshop shall be implemented similar to LAM (Laser Additive Manufacturing) Workshop, which is the Laser Welding & Joining Workshop being held in October. Also, a workshop on ultrafast processing is in the works for 2013.

On a personal note, Poprawe is married to Anette and they have four children. He loves sailing (has all these papers you need for doing it all on your own), snowboarding, philosophy, lyrics, plays golf once in a while and has a great passion for art (does some painting) and music. Convinced of the relevance of high quality and cultivated comprehensive language, he founded an initiative for the local theatre in Aachen, where he serves as a member of the board. Here’s wishing Reinhart Poprawe a successful year as LIA president!

Executive Committee

President Elect Klaus Löffler graduated from the University of Stuttgart with a master’s in mechanical engineering. Since 2009 he is responsible for the strategic industry development for the TRUMPF Laser und Systemtechnik. In 2004 he founded the Automotive Laser Conference in Wolfsburg, Germany, which together with ALAW and JALAW builds a global conference partnership. In 2006 he took over international sales at TRUMPF Lasers and Systems and in 2007 became an LIA board member. Beside LIA, he serves on the board of the SLT conference and other events with the goal to ensu re the global growth of laser technology.

Treasurer Yongfeng Lu is currently the Lott Chair Professor of Engineering at the University of Nebraska Lincoln. Lu received his BEng degree from Tsinghua University (China), M.Sc. and Ph.D. degrees from Osaka University (Japan) in 1984, 1988 and 1991 respectively. Besides the fundamental research work that led to a large number of publications and a number of national and international awards, he also has successfully developed a number of laser-based material processing technologies and commercialized them in industries. In the past few years, he received around $10 million of research funding from DoD, NSF, DOE, NRI, private foundations and industry, including a MURI grant from ONR. He served as the general chair for ICALEO in 2007 and 2008.

Secretary Robert Thomas received his B.S. degree in physics from Pittsburg State University, Pittsburg, KS in 1989 and his Ph.D. in physics from the University of Missouri–Columbia in 1994. He has worked in the areas of experimental and theoretical biomedical optics with the USAF Research Laboratory at Brooks City-Base, Texas. From 1996 to 2002 he served as a research physicist with TASC and Northrop-Grumman Corporation. In 2002 he joined the USAF Research Laboratory where he holds the title of principal research physicist. He has authored and co-authored more than 25 peer-reviewed papers and more than 50 contributed papers. In 2007 Thomas was named a fellow of the LIA.

Immediate Past President Stephen Capp is CEO of Laserage Technology Corporation. He previously held positions as plant manager and president of operations. Laserage is an international supplier of laser-processed materials growing to one of the largest laser job shops in the U.S. He graduated from Milwaukee School of Engineering in 1978 with degrees in electrical power engineering technology and industrial management and has worked in the laser industry for more 30 years. He has been a member of the LIA since 1992.

2012-14 Board of directors

Lutz Aschke, Ph.D., has been managing director and CTO of LIMO Lissotschenko Mikrooptik GmbH in Germany since 2006. From 2004 until 2006 he served as technical director at the executive board of LIMO. Additionally, since 2007 he is member of the board of IVAM, the international association of companies and institutes in the field of microtechnology, nanotechnology and advanced materials. Since 2011 he has been a member of the board of stakeholders of the European Photonics21 initiative. His scientific background is in plasma physics, especially DUV optics, EUV light sources and laser fusion.

Neil Ball is the president of Directed Light Inc, San Jose, CA, a laser technology company serving the industrial, medical and scientific laser communities worldwide since 1983. Ball has devoted his adult working life to the industrial laser industry. He began his career 26 years ago as an application technician in the contract manufacturing sector at LaserFab, Inc. in California. He moved to Systron Donner Inertial and became involved in the production of inertial guidance packages, accelerometer, gyroscopes and inclinometers. Ball joined Directed Light in 1993 to assist in applications development, system design and component/service support. He has led the marketing and developing sales plans for both national and international arenas and is the resident methodologist, working on projection of future industry trends.

Milan Brandt is a professor in advanced manufacturing in the School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Melbourne Australia, focused in the area of additive manufacture using selective laser melting technology. The school is a leading provider of teaching and research locally and internationally in these disciplines. Brandt is the leading Australian researcher in the area of macro machining with lasers. This has resulted in technological achievements, patents, research papers and commercial products that have been recognized internationally and nationally. He was involved in setting up the company Hardwear to commercialize this technology. He has also actively promoted the benefits of laser technology to Australian industry through invited presentations, conference papers and industry seminars. Professor Brandt is a fellow of LIA and was involved on the organizing committees for ICALEO, serving on the board of LIA and being the organizer and general chair for the PICALO 2004 and 2006, which promoted industrial lasers and applications in the region.

Michael Francoeur began his welding career in 1977 as an entry-level employee at an electron beam welding job shop. In 1985 he formed his first company, Dynamic Electron Beam Corp, which he in 1992 and opened Energy Beam Labs, Inc. in Cheshire, CT. Francoeur had changed the original business model used at Dynamic such that Energy Beam’s charter would be to provide research/development and engineering services to a variety of industries in need of precision welding. In 1995, Francoeur went through the entrepreneurship education curricula at Harvard Business School and MIT, which lead to the next reinvention of his business and in 1998 launched Joining Technologies. The new vision targeted laser welding as the principle offering with electron beam as a supporting technology. Joining Technologies has nurtured several strategic alliances, most notably with Fraunhofer ILT in Aachen, Germany.

Lin Li is director of the Laser Processing Research Centre at The University of Manchester; he started laser-processing research in 1985 at Imperial College, London University, with Professor Bill Steen. After obtaining a Ph.D. in laser processing, he worked for six years in the Laser Group, Liverpool University. In 1994, he took up a lectureship (assistant professor) at the University of Manchester Institute of Science and Technology. Li is the author and co-author of over 500 publications in laser processing including 45 patents and over 250 publications in peer-reviewed journals. He was awarded a fellow at the Institute of Engineering and Technology, International Academy of Production Engineering (CIRP), LIA and the International Society of Nanomanufacturing. He serves on the editorial boards of nine international journals and co-chaired the Laser Materials Processing Conference at PICALO 2008 and 2010.

Bill O’Neill is a leader in laser engineering within the Cambridge University Engineering Department and director of the Centre of Industrial Photonics. He has written and researched widely on the subjects of laser-matter interactions, optical engineering, laser based manufacturing technologies and micro/nano fabrication techniques. He is a fellow of LIA and the Institute of Physics and an industry and governmental advisor on a number of laser-based manufacturing technologies. He has established a number of university spin-out companies.

Henrikki Pantsar is director of research and development of Cencorp Corporation. He has more than 10 years experience in developing industrial laser applications and systems for various industries. Before joining Cencorp in 2010, he worked in the laser processing research groups Fraunhofer USA, Inc. in Michigan and VTT Technical Research Centre of Finland. He received his Doctor of Science degree from Lappeenranta University of Technology. He has authored more than 40 publications for international conferences and scientific journals. He received the Henry Granjon Prize of the International Institute of Welding in 2006. Henrikki is a regular presenter, program committee member and chairman at ICALEO conferences, and was the LMF conference chair at ICALEO 2011.

Nathaniel R. Quick is a past president, past secretary, a current executive committee member and fellow of LIA, president and chief technical officer of AppliCote Associates, LLC, Lake Mary, FL, a technology development and licensing company and CTO of !nflect, LC, a technology licensing firm. AppliCote Associates collaborates with academic institutes, including the University of Central Florida/CREOL. Quick has a Ph.D. from Cornell University in materials science and engineering and is a UCF Florida Photonics Center of Excellence advisory board member, UCF Industrial Advisory Committee member, a fellow of the African Scientific Institute, a past guest researcher at NIST and past member of the Army Science Board. He currently holds 39 U.S. patents and has over 60 publications.

Koji Sugioka is a senior research scientist at RIKEN – Advanced Science Institute and a guest professor at Tokyo University of Science and Tokyo Denki University. He received B.E., M.E. and Ph.D degrees in electronics from Waseda University in 1984, 1986 and 1993, respectively, and joined RIKEN in 1986 where he has worked on doping, etching and deposition of semiconductors and surface modification of metals using excimer lasers. Sugioka has received seven awards for his research, inventions and contributions in the area of laser microprocessing. He has published more than 130 articles, has given more than 80 invited talks at international conferences and about 90 invited talks domestically, has 30 patents or pending patents and served as a conference chair, co-chair and committee member for numerous international conferences. He is also editor-in-chief of Laser Micro/Nanoengineering.

Kunihiko Washio is founder and president of Paradigm Laser Research Ltd., Tokyo, Japan, since 2003. He received his M.S. degree in physics from the University of Tokyo in 1968 and Ph.D. degree in engineering from Tohoku University in 1980. He joined NEC Corporation in 1968 and engaged in R&D of various solid-state lasers and their applications for about 35 years. After retiring from NEC in 2003, he has been serving industries in consulting on development of lasers and their applications to materials processing. He has served as a program committee member for the International Symposium on Laser Precision Microfabrication since 2000 and a conference chair for ICALEO’s Laser Microprocessing (LMF) Conference for two years. He was the ICALEO 2011 Congress General Chair.

2011-2013 Board of Directors

Eckhard Beyer, Fraunhofer Institute for Material and Beam Technology
Ken Dzurko, SPI Lasers, LLC
Richard Harvey, Roswell Park Cancer Institute
Markus Kogel-Hollacher, Precitec Group
David Krattley, Preco Inc.
William Lawson, New Tech Development
Juan Pou, University of Vigo
John Tyrer, Loughborough University
Steven Weiss, Innovative Laser Technologies

2010-2012 Board of Directors

Magdi Azer, GE Global Research
Craig Blue, Oak Ridge National Laboratory
Paul Denney, Lincoln Electric
Larry Dosser, Mound Laser & Photonics Center, Inc.
Thomas J. Lieb, L*A*I International
Xinbing Liu, Panasonic Boston Laboratory
Andreas Ostendorf, Ruhr-University Bochum
Islam Salama, Intel Corporation
Bahaa E. A. Saleh, CREOL, University of Central Florida
Michael Schmidt, Bayerisches Laserzentrum GmbH

With more therapeutic procedures moving into private medical offices and homes, the standard regulating the safe use of lasers in health care has undergone a much-needed update to ensure users, as well as patients, are protected.

The revised “ANSI Z136.3 Safe Use of Lasers in Health Care” publication defines the parameters of proper laser use outside the tightly regulated hospital environment. Formerly titled the “American National Standard for Safe Use of Lasers in Health Care Facilities,” the revision released in January includes new guidelines and information on:

• Wavelengths employed in medical environments. While some lasers are no longer listed, at least four new wavelengths have been added.

• The duties of laser safety officers involved with rented or borrowed laser equipment.

• Audit requirements and procedures.

• Clinically relevant terminology.

The comprehensive ANSI Z136.3 standard, reformatted to appear more reader-friendly, addresses everything from laser systems hazard classification, to protective equipment, to non-beam hazards and room design. One of six ANSI Z136 laser safety standards in use, the revised ANSI Z136.3 standard serves to “acknowledge the diversity of laser therapy applications and practice setting locations,” according to Peter Baker, LIA’s executive director.

“The change is quite significant in that previous versions looked at the location in which a laser was used,” notes Barbara Sams, executive director of the Board of Laser Safety, an LIA affiliate. “This change, instead of looking to the specific location, is looking at the application being administered by people for any type of health-care related purpose.”

“In this revision, more consideration is given to the people using the laser,” she continues. “The patient comes first, of course. However, when a patient is being operated on, they could be under anesthesia, they should have the proper protection over their eyes; they’re protected. A greater focus has been placed on the people who are actually in the room using the laser — the surgeons, nurses, technicians, anesthesiologists, extending to veterinarians, laser hair removal facilities and even home use.”

The new standard “is a must-read for every LSO and facility providing laser-based therapy,” says Sue Terry, registered nurse and ANSI Z136.3 subcommittee member. “It is a pleasure to see that sample forms and documentation records remain a part of the appendix. These examples have long proven to be beneficial when establishing or revising a laser safety program.”

Fellow committee member Patti Owens, also a registered nurse and certified medical laser safety officer, is equally excited about the revision. “As an experienced LSO in a hospital, dermatology practice and recently as an aesthetic/medical consultant, I am looking forward to … the new ANSI Z136.3 standard,” she enthuses. “My clinics are already being advised of the upcoming changes and will begin the implementation phase once the document has been published.”

The new standard is serving its vital purpose across a broader range of therapeutic uses. For example, the Association of Surgical Technologists will review the new guidelines to inform the update of the AST’s “Recommended Standards of Practice for Laser Safety,” says Kevin Frey, director of continuing education for the organization.

In the meantime, veterinary medicine has finally seen its laser-use needs addressed.

“There was a seven-year effort to have veterinary medicine included in the .3 document as well as included as an appendix,” says Kenneth Bartels, who serves as the American Veterinary Medical Association’s liaison to ASC Z136. “These inclusions were considered a priority since in some medical circles, laser use in veterinary medicine was considered totally different (from other uses). Laser manufacturers that market to veterinarians have for the most part provided excellent outlines for the safe use of their devices in veterinary medicine in the respective operator manuals. With the new .3 guidelines, for some manufacturers those efforts may be intensified.”

LIA, the recognized industry leader in laser advocacy and safety education since 1968, serves as secretariat of the Z136 series of laser safety standards, administering the process and providing clerical support to the committee. To order the ANSI Z136 .3 revision ($130 for LIA members, $150 for non-members), visit www.lia.org/ANSI.3 or call LIA at 1.800.34.LASER.

The environment continuously attacks our infrastructure in a way that is less spectacular than, for example, earthquakes or hurricanes, but far more expensive. Corrosion affects most surfaces, but especially metallic ones, on a daily basis and costs around 3–6% of developed countries’ GDP to combat. In the US alone corrosion costs are an estimated $276 bn/year, compared to the average annual cost of around $13 billion due to hurricanes. [1,2]

Corrosion can be combatted, however this can be expensive and it is necessary to match the method to the surface for it to be cost effective. For larger, low-cost parts such as pipes and bridges, painting, and if necessary repainting when necessary, remains popular. For higher value parts, such as car panels or chassis, zinc coating applied via electroplating is a common method. For the highest value parts, for example in the aerospace industry, a corrosion-resistant material may be used for the complete component.

Laser Cladding is a method of surface coating by powder fusion that is used when high performance, wear or high temperature corrosion resistance is required (aerospace engines, power stations etc). It traditionally uses spherical metal particles of smaller than 100 um diameter as the raw material for the coating. During the cladding process these are propelled into a melt pool created by a laser moving across the surface of the material to be protected. When this melt pool solidifies it forms a solid layer fused to the original surface and this then acts as a passive barrier to corrosion. A typical protective clad layer is shown in Figure 1. [3]

Typically, laser cladding is relatively expensive method, partly due to the capital cost of the equipment but mainly due to the cost of the spherical, gas-atomised powder. However, recent work has shown that it is feasible to use prepared machining swarf instead of this powder without compromising the corrosion-resistance of the final layer. This reduces material costs to close to zero, and potentially dramatically increases the range of application of the method. Figure 2 compares the powder that has typically been used and the new prepared swarf. [4]

The reduction in corrosion that can be provided by a clad swarf layer is dramatic. For example, corrosion tests in a NaCl solution reveal that the corrosion rate of uncoated mild steel was 34.7 mm/year, while that of the same samples laser clad with Inconel 617 swarf was less than 0.1 mm/year [5]. Using greater laser energy per unit area during the deposition of the protective layer further enhances the corrosion resistance, probably because it leads to a coarsening of microstructure, reducing the number of grain boundaries (Figure 3).

So, the combination of the reducing capital cost of lasers and now low material costs make laser cladding a weapon that could be used more widely in the battle against corrosion. It remains only one of many methods, but when faced with an annual bill of $276 bn/year any improvement offers significant cost savings.

Due to their excellent strength, chemical resistance, and optical transparency, glass materials are widely used in consumer electronics such as in flat panel TVs, laptops, and hand-held devices.  Small to medium form factor glass panels (3 to 10 inch), in particular, are enjoying a very healthy annual growth of close to 20% thanks to the recent boom in high end smart phones, e-readers, and tablets.

An anatomy on most of these popular gadgets reveals several layers of glass panels:  first is a strengthened piece of cover glass that has extremely high compressive stress to protect the devices from impacts, scratches, stains, and harmful chemicals.  Underneath the cover is a thin layer of glass deposited with two-dimensional ITO patterns (in most cases) to support touch functions.  Display glass such as LCD or OLED modules lies beneath these two layers and provides vivid images and video playbacks at high contrasts.  Different functions of these glass substrates require different designs:  on the cover glass curvilinear and internal features are needed to generate rounded corners, streamlined perimeters, speaker holes, and home buttons.  Touch panel and display module generally only need straight cuts for panel singulation from a mother sheet.

Established glass machining methods include mostly mechanical scribing, manual breaking, and mechanical grinding and polishing.  As the industry move forward, consumers demand better protection, function, design, and structures for these glass panels which lead to thinner and stronger substrates for reduced weight and volume.  This has resulted in great challenges for mechanical processes in terms of cut quality, yield, and throughput.  Laser glass machining tools provide non-contact machining with minimum impact and superior quality compared to the mechanical counterparts.  As their power grows higher and price becomes cheaper lasers are increasingly used in glass machining applications.

Different lasers are used for machining glass depending on the functions and features of the panels.  For straight line cutting in touch panel and display glass, CO₂ lasers are used to trigger a controlled thermal cleaving (CTC) process thanks to their high linear absorption in glass at the 10.6um wavelength.  A large tensile stress (up to 200 MPa) can be generated by following the CO₂ ‘scribe’ beam with a quenching jet of water-air mist.  This is enough to tear the glass surface open when a crack already exist – usually a surface crack initialized at the edge of the glass by a mechanical scribe or laser shot.  The crack only penetrates partially into the substrate so the glass is still held together after this ‘scribe’ step.  Usually a manual break follows to separate the glass which can be done by a breaker system or a human operator.  At ESI we use a second laser beam (the ‘break beam’) to fully propagate the crack and singulate the panels in one step.  This proprietary technology – laser full cut – reduces the process steps and increase cut facet quality.

Figure 1 shows a schematic process flow for the laser full cut method (a) and the high edge quality from a laser singulated 1.1-mm panel.  Cutting speed ranges from 200 to 500 mm/s depending on the glass type and thickness.

When curvilinear and internal features are needed a laser direct ablation process is used.   DPSS lasers in the nanosecond and picosecond pulse width can trigger efficient nonlinear absorption in glass due to their high peak intensities.  Both IR (around 1um) and its second harmonic generation (~0.5 um in green) can be used to cut glass layer by layer but green wavelength gives better edge quality.  At different pulse duration, a green picosecond laser (~2W, 200 kHz, 10ps) provided 10x higher edge quality (0.5 um surface roughness) but 10x slower material removal rate (5 um³/uJ) compared to a green nanosecond laser (~2W, 20 kHz, 10ns).  Furthermore, for the chemically strengthened substrates such as the Corning Gorilla glass, only the picosecond laser was able to cut through without cracking the glass.  Material removal rate of both ns and ps lasers scales with laser power and we have recently demonstrated effective cutting speed of ~3 mm/s through a 0.7-mm thick Gorilla glass by using a 50W green picosecond laser. 

Figure 2 shows a 10-mm diameter hole and a 20x30mm rounded rectangle cut from a 0.7-mm thick Gorilla glass with high quality water-clear edge.

As the glass market evolve, glass substrates are getting even thinner and stronger than ever before.  Laser machining tools with high quality cut and competitive throughput are expected to play more important roles in the consumer electronic device manufacturing processes.

The revised “ANSI Z136.3 Safe Use of Lasers in Health Care” publication defines the parameters of safe laser use in clinical, hospital, dentistry and veterinary facilities. The revision released this month includes new guidelines and information on:

• Wavelengths employed in medical environments.

• The duties of laser safety officers involved with rented or borrowed laser equipment.

• Audit requirements and procedures.

• Clinically relevant terminology.

The comprehensive ANSI Z136.3 standard, reformatted to appear more reader-friendly, addresses everything from laser systems hazard classification to protective equipment to non-beam hazards and room design. One of six ANSI Z136 laser safety standards in use, the revised ANSI Z136.3 standard serves to “acknowledge the diversity of laser therapy applications and practice setting locations,” according to Peter Baker, LIA’s executive director.

“The change is quite significant in that previous versions looked at the location in which a laser was used,” notes Barbara Sams, executive director of the Board of Laser Safety, an LIA affiliate. “This change, instead of looking to the specific location, is looking at the application being administered by people for any type of health-care related purpose.”

“In this revision, more consideration is given to the people using the laser,” she continues. “The patient comes first, of course. However, when a patient is being operated on, they could be under anesthesia, they should have the proper protection over their eyes; they’re protected. A greater focus has been placed on the people who are actually in the room using the laser — the surgeons, nurses, technicians, anesthesiologists, extending to veterinarians, laser hair removal facilities and even home use.”

The new standard “is a must-read for every LSO and facility providing laser-based therapy,” asserts Sue Terry, registered nurse and ANSI Z136.3 subcommittee member, in reviewing the new standard. “It’s a pleasure to see that sample forms and documentation records remain a part of the appendix. These examples have long proven to be beneficial when establishing or revising a laser safety program.”

LIA, the recognized industry leader in laser advocacy and safety education since 1968, serves as secretariat of the Z136 series of laser safety standards, administering the process and providing clerical support to the committee. To order the ANSI Z136.3 revision ($130 for LIA members, $150 for nonmembers), visit www.lia.org/ANSI.3 or call LIA at 1.800.34.LASER.

Friction creates a loss of energy and reduces component lifetime. According to the scientific community concerned with friction, wear and wear protection the overall costs related to these issues amount to 4 % of the Gross National Product of industrial countries, a staggering sum. Despite the fact that wear protection coatings are already deployed to improve the life-time of highly stressed components, limiting costs due to tribological loss mechanisms poses a great challenge in many industrial sectors. In particular, within the automobile sector, a high throughput of parts needs to be protected every year. As a consequence there is a strong demand for low-cost production processes for wear protection coatings.

Physical vapor deposition (PVD) is a widely accepted technology to produce high-performance wear protection coatings. It exhibits, however, several distinctive drawbacks such as its high demand for a great amount of technological efforts and the inherent costs as well as the lack of inline-capability. As a low-cost alternative to PVD, wet-chemical processes based on nanoparticulate materials hold great potential as they do not need expensive vacuum technology or any other elaborate equipment. In addition, they can also easily be integrated into an inline process chain.

The FunLas research consortium consisting of Schaeffler KG, Merck KGaA Darmstadt, Biofluidix GmbH, DILAS GmbH and the Fraunhofer ILT has succeeded in producing innovative wear resistant coatings based on such nanoparticulate material. Sponsored by the German Federal Ministry of Education and Research, the jointly run project aims to develop a cost-effective laser-based inline production process.

The overall process can be divided into three steps. At first the sol-gel coating mixture consisting of nanoparticulate zirconia dispersed in a mixture of solvents and additives is applied to hardened steel substrates via dip- or spin-coating. These are energy and resource-saving techniques that are easy to implement. During the coating process evaporation of the main part of solvents takes place. Within the second step the remaining solvents are removed by heating the samples to 150 °C. After drying the deposited layer is about 300 nm (Figure 1).

[Figures 1a and 1b, Coated samples with different geometries (a). SEM-micrograph of a coated sample (b)]

Finally the major challenge of this innovative coating process is to implement a thermal post treatment at temperatures > 800 °C, required to achieve functionalisation of the applied films. In this case the functionalisation refers to all processes, such as densification of the coating, that lead to improving the layer hardness and mechanical stability significantly. During this thermal post treatment it is necessary to minimize the thermal load of the steel substrates, which often feature low tempering resistance. Due to its exact local and temporal controllability, the laser is very well suited for this purpose.

In order to fulfill the complex task of generating temperature-time-profiles that meet these two opposing requirements the experimental work is supported by the following modeling approach. In a first step the splitting-up ratio of the laser energy absorbed in the coating and in the substrate is calculated based on the determined optical constants of the coating material. Knowing that 17 % of the overall laser power is absorbed by the coating whereas 29 % is absorbed by the substrate the heat conduction equation is solved for specific sets of process parameters. According to this simulation it is possible to realize a peak temperature of 800 °C at the surface of the coated sample while the heat affected zone is reduced to approximately 20 µm when using pulsed diode laser radiation at a wavelength of 980 nm and an intensity of 4 · 10⁵ W/cm² (Figure 2b). This is a significant improvement compared to the minimum heat penetration depth of approximately 90 µm realized when continuous diode laser radiation at an intensity of 1.4 · 10⁵ W/cm² is used to generate a peak temperature of 800 °C.

[Figure 2 a and b, FEM-results of the temperature-time-profile at the surface of  the coated steel substrate demonstrate the correlation between the depth of the heat affected zone and the interaction-time between the laser-beam and the sample (a). According to this simulation the heat penetration depth is reduced to 20 µm when using pulsed diode laser radiation at a pulse intensity of 4 · 10⁵ W/cm² and a pulse duration of 20 µs to generate a peak temperature of 800 °C (b)]

This significant decrease is due to the reduction of the interaction-time between the laser beam and the coated sample during the laser treatment which is realized with a beam deflection system by guiding the laser beam in meandering loops (Figure 3). The interaction-time, which refers to the period during which energy is transferred to an element of the coated surface is determined by the pulse duration between 2 – 20 µs when using pulsed laser radiation. When continuous diode laser radiation is used, on the other hand, this time is determined by the period required to cross the beam diameter of 340 µm at a given scan velocity. Due to the large size of the mirrors used within the beam deflection system to guide the raw laser beam with a diameter of approximately 30 mm, the scan velocity is limited to 2000 mm/s which results in a minimal interaction time of 170 µs in the latter case.

[Figure 3, Schematic view of the laser setup and the laser treatment strategy]

In accordance with the laser treatment strategy shown in Figure 3 there are four laser process parameters for the laser hardening process with pulsed diode laser radiation: The pulse energy E_P, the pulse duration t_p, the track offset d_y and the number of pulses per position n which is the number of pulses deposited during the period required to cross the beam diameter at a given scan velocity. Based on the information obtained by FEM simulations these parameters are adapted systematically to achieve an optimal result. Important information about the mechanical properties of the coatings is obtained by means of nanoindentation hardness measurements carried out with a fisherscope HM500. These measurements, carried out with a Vickers indenter, a test load of 0,5 mN and a load time of 20 s, prove that the laser treatment was successful. By increasing the number of pulses per position the coating hardness is increased to approximately 800 HV (Figure 4). This is a significant improvement compared to an untreated coating (n=0) with a hardness of approximately 160 HV. Therefore the laser treatment led to a substantial reduction of the discrepancy between the hardness of the sol-gel coating and the reference coating produced by PVD. With regard to the low costs of the laser based process this is an incredible success.

[Figure 4, Vickers hardness of dried (n=0) and laser treated coatings (n = 1, n= 4,5) compared to the hardness of a coating produced by PVD, measured with a test load of 0,5 mN and a load time of 20 s (n refers to the number of pulses per position)]

Further investigations on the wear protection performance of the laser treated coatings are carried out by applying an industrially approved FE8-test-procedure. This test is carried out by Schaeffler KG in order to evaluate the protection performance of the laser treated coatings under realistic operating conditions. During this test carried out at loads of 30, 50 and 80 kN, the laser treated coatings show performances similar to currently used ceramic or diamond-like coatings produced by PVD (Figure 5). With these promising results the FunLas consortium has moved a step closer to the aim of developing an inline-capable, cost-effective process as an alternative for conventional PVD-processes.

[Figure 5, Comparison of Fe8-tested sample surfaces (diamond-like coatings produced by PVD (a) and laser-treated ceramic coating (b))]

Credit is due to the German Federal Ministry of Education and Research for funding the research depicted in this article within the framework of the funding measure “Material Processing with Brilliant Laser Sources” (MABRILAS). The author would also like to thank the Schaeffler KG, Merck KGaA, Darmstadt and DILAS GmbH for the excellent cooperation within the project consortium FunLas.

Why is Aluminum Welding such a Hot Topic?

New CAFE standards demanding an average fleet gas mileage of 54.5 mpg by 2025 will not only require radical engine improvements, but also drastically weight reduced cars. Using aluminum instead of steel can decrease the weight of a car body up to 50%, as shown in the Audi A8, which was 239 kg lighter than its steel predecessor when it was introduced in 1994.

Joining aluminum initially represented quite a challenge, but is now mainly solved with riveting, MIG welding, and to a large extent by laser welding, enabled by new laser technologies.

Laser welding of aluminum

Diode lasers offer a distinct advantage for aluminum joining: At 900 to 1060 nm, the wavelength of the diodes is closer to the absorption peak of aluminum than the 1030 nm of disk or 1070-1080 nm of fiber lasers. Several car manufacturers have carried out extensive development and testing programs, and now use diode lasers for structural welds as well as outer skin joints.

In general, welding 6000 series aluminum which is commonly used in car bodies requires an AlSi filler material to prevent hot cracking of the weld. The laser welding equipment is largely the same as the industrially proven components used in the brazing process, where the filler wire is added using tactile seam tracking optics.

After a multi-year development project, Audi decided to use a 4 kW diode laser with a 400 µm fiber to weld the aluminum tailgate of several vehicles, and is running this system on their production floor. The finish of the zero-gap weld on the tailgates meets the highest specifications for the optical quality of a visible joint without further post-processing (see Figure 1).
Kuka North America has successfully used both a 4 kW / 400 µm laser and a 6 kW / 1000 µm laser for aluminum welding, depending on the joint requirements. Typical weld speeds are 3 to 4 m/min. One more unusual application was to weld structural reinforcements under truck beds. This was achieved by using a low brightness diode laser with a 1 µm fiber. It yields an edge lap weld with good weld strength yet very little to no show on the backside (see Figure 2a).

A different type of edge lap welds is used in structural applications where no optical requirements exist. Here, it is important to get as much strength as possible. Figure 2b shows a structural edge lap weld using a 4 kW diode laser, 0.8 mm spot size, at a 3 m/min processing speed. Notice the much wider area of the joint and the bump on the underside of the material.

LIA held its most recent on-site Industrial Laser Safety Officer (ILSO) course Dec. 13-14 at IPG Photonics in Novi, Mich., with attendees learning the duties of laser safety officers (LSOs). Laser-based cutting, welding, drilling, and marking applications are being adopted with greater frequency, and manufacturers are scrambling to appoint and educate LSOs to ensure the safety of their personnel.

Among LIA’s broad repertoire of renowned laser safety resources, the on-site LSO course hosted by IPG provides a vital opportunity to connect with experts in the field. The December session — the fourth the LIA corporate member has hosted this year — was so popular that LIA Education Director Gus Anibarro had to turn away some prospective attendees.

Hosting the ILSO course at locations closer to industry hubs — for example, the automotive industry of the Midwest — is invaluable to firms that can’t send employees to LIA headquarters in Orlando, notes Mike Klos, IPG’s general manager of Midwest operations. “We provide the room, and at the end we give a demo with the high-powered laser in the back lab here. We say, ‘Hey, I know you don’t understand the 1 micron wavelength — it’s a little bit different, but we do have LSO training and highly recommend it if it’s not mandatory for your company.”

The highly focused course emphasizes the basics, says instructor Tim Hitchcock, “To help (attendees) understand the hazards of industrial laser use and how to establish a laser safety program to control these hazards.” The on-site model “helps the host provide a necessary service to their customers and allows the customers to focus on the essentials of laser safety for their particular work environment.”

Attendees get an overview of safety regulations, the bioeffects of lasers, proper control measures, and effective program administration. The registration fee ($550 nonmembers, $500 members) includes a CD packed with useful LSO forms. Also included with the course are LIA’s Laser Safety Guide, relevant ANSI Z136 Standard, LIA’s Guide to the Selection of Laser Eyewear and more.

The on-site ILSO sessions are tailored to fit the needs of safety professionals, engineers, laser operators, technicians, and other professionals assigned LSO duties without being required to perform hazard analysis calculations. The Dec. 13-14 workshop included attendees from Pratt & Whitney, Eagle Technologies, American Axle Manufacturing, and the Automatic Feed Company.

Going into this course, attendees can expect to learn about how to determine hazard zones, select the correct protective eyewear, and be informed on the best way to keep themselves and company personal as safe as possible. “I learned all of that, as well as exactly how exposure affects the eyes and skin, a good deal of technical terminology, and how the ANSI Z136.1 standard is set up to help develop a solid laser safety program,” says course attendee Josh Boyd, Controls Engineer at Automatic Feed Company, “through some examples of past accidents as told by our instructor, I also developed an even greater respect for the dangers that lasers can pose, even if they are lower power lasers”.

LIA, the recognized leader in laser advocacy and safety resources since 1968, is rapidly filling its 2012 calendar with industrial and medical laser safety officer courses. Visit www.lia.org/education/calendar to view the current schedule and register. Firms and organizations wishing to host a laser safety officer course can visit www.lia.org/education/inhouse for more details, or receive a customized quote by contacting LIA at 1-800-345-2737 or courses@lia.org.

Since its first edition in 2006, LASER World of PHOTONICS CHINA, the affiliated trade fair to the LASER World of PHOTONICS network forAsia, has become a leading trade fair showcasing the full range of laser and photonics innovative products, new solutions and technologies reflecting international trends in the world. During its 3-day show in 2011, it has attracted 361 exhibitors from 18 countries and districts, an increase of 31% compared to 2010, as well as 28,845 professional visitors from 48 countries and districts. These record numbers confirm its leading position in the Asian laser and photonics market.

PHOTONICS CONGRESS CHINA will be held in conjunction with LASER World of PHOTONICS CHINA 2012 for the first time. It includes the 7th International Conference on Laser Processes and Components (LPC 2012) – in cooperation with LIA, Optics Frontier – The Seventh Laser Technology Forum and Outstanding Achievements Release Conference of Chinese Optics 2011, the Optoelectronics Industry Development Association Workshop on Optical Communications and the OSA Energy Photonics Program.China (Shanghai) Machine Vision Technology & Application Conference will also be held as an accompanying program at the trade fair. The combination of scientific, research and industrial applications both in the conferences and the trade fair support the exchange between the scientific and industrial sectors and underscore its unique practical value.

For more information, please visit: www.photonicschina.net

ORLANDO, FL, Dec. 19, 2011— The fourth-annual Laser Additive Manufacturing Workshop in Houston takes a bold leap forward in 2012 as the Laser Institute of America creates a special slate of instruction focused exclusively on rapid manufacturing.

Whereas the two-day session has centered primarily on laser-based rapid prototyping and powder and wire cladding to repair corrosion and wear, LAM 2012 will spend one day on those traditional applications and devote a full day to 21^st century strides in sintering and 3D printing. The Feb. 29 – March 1 workshop convenes in Houston once again because of the laser’s vital role in the region’s oil and gas industries.

Embracing the Future

Renowned U.S. rapid-manufacture expert Terry Wohlers, who lent his expertise to The Economist’s February 2010 edition featuring a cover story titled “Print Me A Stradivarius,” has been invited to address attendees. In a story titled “The Printed World,” he noted that more than 20 percent of the output of 3D printers is final products; he expects this to rise to 50 percent by 2020.

“Additive manufacturing systems that produce parts in metal have progressed tremendously in 10 short years,” notes Wohlers, who began his consulting firm Wohlers Associates (wohlersassociates.com) in Fort Collins, CO, 25 years ago. “Some of the parts approach the mechanical properties of wrought materials and exceed those of cast parts. This is not in all cases, but it is not uncommon.”

Additive manufacturing permits designers to produce highly complex shapes and features that would be difficult or impossible to produce any other way, he notes. “This is allowing companies in aerospace, medical and other industries to explore more advanced designs that dramatically reduce material, cost, weight and carbon emissions.”

A prime example is the “Airbike” built in March by the European Aerospace and Defense Group (EADS) in Bristol, U.K. The bike is so named because of Airbus’ reliance on the additive layer manufacturing process, EADS notes. “Made of nylon but strong enough to replace steel or aluminum, it requires no conventional maintenance or assembly,” EADS says on its website. “(The bike) is ‘grown’ from powder, allowing complete sections to be built as one piece; the wheels, bearings and axle being incorporated within the ‘growing’ process and built at the same time. The Airbike can be built to rider specification so requires no adjustment.”

Dr. Bill O’Neill of Cambridge University, who noted the Airbike during his presentation at LIA’s first Lasers for Manufacturing Event (www.laserevent.org) in September, said additive processes are supplanting the Victorian manufacturing model. Dr. Ingomar Kelbassa of Germany’s Fraunhofer ILT and RWTH Aachen University concurs.

“We’re not talking about rapid prototyping any longer; we are talking about rapid manufacturing out of metals, polymers, out of any kind of ceramics,” Kelbassa says. “This is a paradigm shift in manufacture. From the Stone Age, we have been producing parts subtractively; we are removing material. You are throwing away 90 percent. Subtractive manufacturing isn’t as effective as additive manufacturing in terms of saving material, time or money. Now we are talking about … building up the part from scratch.”

In other words, what was once the realm of science fiction has become reality.

“Remember ‘Star Trek’?” Kelbassa asks. “’Replicator: Tea. Earl Gray. Hot.’ The cup is there with the tea in it. It’s just there, additively manufactured.”

Laser Additive Offerings

Besides the Airbike, highly localized personalized laser additive manufacture has been explored with great success within the past 10 years, he notes. For example, larger parts such as bumpers can be manufactured additively stereolithography. And since 2002, Germany’s BEGO has been using what Kelbassa calls Selective Laser Melting (SLM) to produce patient-specific dental bridges, implants, and crowns.

“This was the first industrial implementation,” Kelbassa says. “From the material point of view, from the maturity point of view, from the technology readiness point of view, (SLM) is ready for industrial implementation.

Wohlers notes that CE certification for the process in Europe four years ago has allowed many European manufacturers to produce orthopedic implants using additive manufacturing. For instance, he says an estimated 15,000 acetabular hip cups manufactured in Ti-6Al-4V titanium alloy have been implanted into patients.

“Earlier this year, the FDA approved the use of electron-beam melting for the production of a similar orthopedic product, which marks another milestone,” Wohlers says.

The possibilities are nearly endless. “It’s a pretty short process chain: All you need is the CAD data, all you need is powder, and if you have the CAD data and the powder additive you can produce the part,” Kelbassa says. He imagines a 24/7 global manufacturing process. For example, a Europe-based company with facilities in the Far East and South America can work in three eight-hour shifts: Upon completion of the first shift in Asia, data is transferred to Europe for a second shift, and after that shift the data is sent west again for the third shift.

At the moment, he says, part size is a restriction. And Wohlers notes the cost can be prohibitive, “but a number of service providers own machines and build parts for others.”

At LAM, both men will impress upon attendees that a new generation of engineers is required to take full advantage of what additive manufacturing has to offer.

Discover It At LAM

LAM will once again feature cutting-edge presentations and exhibits by platinum sponsor Alabama Laser, gold sponsors IPG Photonics Corporation, Fraunhofer USA and Joining Technologies, Inc., silver sponsors Coherent, Inc. and Laserline Inc., bronze sponsor TRUMPF, Inc. and others.

Wayne Penn, president of Alabama Laser, and Keith Parker, senior business development manager at Coherent, say they are “excited” to attend LAM 2012. Parker is considering presenting a paper on his firm’s new high-deposition procedure using 8 kilowatt lasers and a 24mm-wide beam to lay down 20mm clads in a single pass. The method could be valuable to the oil and gas industry in cladding the sort of massive shafts used in offshore rigs, he notes.

Looking ahead, Parker — a former F-14 Tomcat pilot — readily sees the possibilities additive manufacturing could offer the military. Imagine an aircraft carrier crew that needs to replace parts during a deployment but can’t take up valuable space on the ship with those spares. In fact, many parts encountered in military service are 40 or more years old; often the blueprints or manufacturers no longer exist, Parker says.

“So where do you get parts when you need them?” he asks. “In a lot of cases they really need to be able to build up those parts. If you had one of those (laser additive) machines on an aircraft carrier and something broke, you could get a CAD model and create it from scratch.” Aerospace, too, he notes, is a likely beneficiary of such technology, because of the complex 3D structures required for turbine engines.

To find out more about what to expect, read coverage of last year’s LAM workshop in the March-April 2011 issue of LIA’s newsletter, LIA Today, available online at http://lia.org/subscriptions/lia_today.

For more information about LAM 2012 and to register, visit http://lia.org/conferences/lam.