Field Of Laser Materials Processing Research Articles

Preface

About the conference:Laser material processing is growing in its importance of manufacturing. In Nordic countries the tradition is carried out with NOLAMP Conference.The first conference on Nordic Laser Material Processing, NOLAMP was held in Oslo in 1987. Then the laser material processing was a rather new and revolutionary way to manufacture products with high quality and high efficiency. The laser research in the Nordic countries was in its pioneering age and the enthusiasm among researchers for the new possibilities was unrivalled. The intention for creating this conference, which was originally suggested by Dr. Bernt Thorstensen at SI in Oslo, Norway, was to establish a fruitful cooperation among Nordic laser researchers. Also, NOLAMP intended to provide a forum for young researchers to present on-going works and to establish contacts in the scientific community as well as in industry.Ever since then, the conference has been reaching its goals and acted as discussion forum between academia and industry in the field. Currently the conference gets growing attention all over Europe also. The conference is now organized 5th time in Finland and this time it is organized in Turku at the south-west coast of Finland. The conference agenda includes various topics in field of laser materials processing and as current trend is, there is quite a lot of papers on the newcomer of laser processing the additive manufacturing.List of Conference date and location, Conference topics, Keynote speakers, Sponsors, Supporters, Scientific Committee members, Editors, Reviewers, National Organizing Committee are available in this pdf.

Laser materials processing of complex components. From reverse engineering via automated beam path generation to short process development cycles.

The article presents an overview of what is possible nowadays in the field of laser materials processing. The state of the art in the complete process chain is shown, starting with the generation of a specific components CAD data and continuing with the automated motion path generation for the laser head carried by a CNC or robot system. Application examples from laser welding, laser cladding and additive laser manufacturing are given.

Experimental Investigation of the Cutting Front Angle during Remote Fusion Cutting

Abstract Remote fusion cutting represents a promising tool in the field of laser material processing. To further promote the practical application of this process, it is necessary to gain additional know-how concerning the process dynamics. In this contribution an experimental investigation of the cutting front angle is presented. This angle is calculated by evaluating recordings of the process with a high speed camera. Analysis reveals the varying influences of the different process parameters regarding the cutting front angle. Furthermore, a process model based on the achieved results is introduced and discussed. Finally, the relevant findings are summarised and an outlook concerning further investigations is given.

Focusing and optical imaging in applied laser technologies

AbstractIn the field of laser material processing the knowledge of the intensity distribution in the processed volume is of considerable importance. Both, manageable algorithms as well as some information about parameters that influence the beam profile, including limiting factors, are relevant for the practical application. This article compares the approach of focusing laser beams with the method using an imaging optical system. Different algorithms are described and practical consequences are discussed.

Welcome to Munich!

AbstractNo doubt the Laser. World of Photonics is the largest trade show for photonic technologies in the world. Optical components and laser technology for industrial applications have been the focal point since its foundation in 1973. Looking at the excellent economic situation in Germany (and it looks even better in the laser industry), one can expect new record numbers of exhibitors and visitors. Furthermore, the accompanying congress and the workshop program are even better and bigger than ever before. Please see our special conference recommendations in the MEETINGS section of this issue for further details. And last but not least, it looks as if we will have a wonderful summer. So you should definitely include an evening in a Biergarten as part of your Munich schedule.A few more words about the World of Photonics Congress: The scientific program at the Laser fair has grown over the years and nowadays represents the largest European meeting on photonics. Yet, there is still some confusion surrounding it. You have about a dozen conferences, seminars and workshops to choose from. The numbers of presentations and visitors at all the events will be impressive, maybe comparable to the numbers at the annual Photonics West conference held in San Jose, CA (excluding ‘trade show only’ visitors). But while SPIE organizes the whole program in the USA, we have as many organizers as conferences in Munich. The results are obvious: You have a number of websites to register for the different events, plenty of different program catalogs (not even a common layout), and of course you have lots of overlap. When German officials announced governmental funding for the conference after the last show, there were hopes for a better organizational structure.Unfortunately, this chance has not been seized. Maybe next time… This special issue of the “Laser Technik Journal” focuses on Laser systems. I have tried to acquire authors from the forefront of current laser R&D to give you a picture of the features and particular advantages of the latest laser systems. One thing is surprising in this respect: CO2 lasers are as important as they have ever been ‐ despite all the success of solid state systems (see market review on page 11 for details). Nevertheless, solid state lasers have made a lot of progress. Disk laser, fiber laser and even diode lasers offer completely new features and will allow for a number of new applications. With a number of systems certified for the German automotive industry (see page 50), the disk laser is in the lead, but the race is just starting…The Laser Technik Journal is a German magazine, principally for the publication of new technologies and applications in the field of laser material processing. Therefore, the Laser. World of Photonics is “the place to be” for LTJ and it is a pleasure for me to partner here with a number of conferences and workshops. This will be Laser Marketplace, Laser in Manufacturing LIM 2008, the conferences of the European Optical Society and several workshops held by the Fraunhofer society. Please check pages 68/69 for more details of our partners' events.The expectations for business and for the weather look bright and I wish you a good time at the Laser.World of Photonics. I hope you enjoy reading the new Laser Technik Journal and I look forward to seeing you in Munich.

The development and characteristics of a hand-held high power diode laser-based industrial tile grout removal and single-stage sealing system

As the field of laser materials processing becomes ever more diverse, the high power diode laser (HPDL) is now being regarded by many as the most applicable tool. The commercialization of an industrial epoxy grout removal and single-stage ceramic tile grout sealing process is examined through the development of a hand-held HPDL device in this work. Further, an appraisal of the potential hazards associated with the use of the HPDL in an industrial environment and the solutions implemented to ensure that the system complies with the relevant safety standards are given. The article describes the characteristics and feasibility of the industrial epoxy grout removal process. A minimum power density of approximately 3 kW/cm2 was found to exist, while the minimum interaction time, below which there was no removal of epoxy tile grout, was found to be approximately 0.5 s. The maximum theoretical removal rate that may be achievable was calculated as being 65.98 mm2/s for a circular 2 mm diameter beam with a power density of 3 kW/cm2 and a traverse speed of 42 mm/s. In addition, the characteristics of the single-stage ceramic tile grout sealing are outlined. The single-stage ceramic tile grout sealing process yielded crack and porosity free seals which were produced in normal atmospheric conditions. Tiles were successfully sealed with power densities as low as 550 W/cm2 and at rates of up to 420 mm/min. In terms of mechanical, physical, and chemical characteristics, the single-stage ceramic tile grout was found to be far superior to the conventional epoxy tile grout and, in many instances, matched and occasionally surpassed that of the ceramic tiles themselves.

超短パルスレーザによる材料加工現象 １ 金属を対象とした改良型分子動力学法の開発

Recently, short-pulse lasers have been applied to microprocessing in the field of various industries. It becomes more difficult to experimentally observe the microprocessing phenomena as pulse width becomes short. Numerical analysis with a continuum model has a limit in elucidation of such phenomena, therefore, computer simulations at the atomic or molecular level must be important. The authors have carried out the molecular dynamics simulation for the first time in the field of laser materials processing and have been making fusion and evaporation phenomena clear at the atomic level. In this paper, a modified molecular dynamics method for metal was developed, in which calculation of the molecular dynamics is carried out compensating the heat conduction by free electrons at each time step. Its validity was confirmed by calculating thermal conductivity and thermal diffusivity. Pulse width dependence of damage threshold was also investigated.

Recubrimientos superficiales con láseres de diodos de alta potencia

Nowadays, high power diode laser systems are available in the market. These systems, based on arrays of small diode lasers, can achieve more than 1 kW of output power and are currently offering new possibilities in the field of laser material processing where CO 2 and Nd:YAG lasers were used up to the present. The results obtained in some materials cladding based on cobalt and nickel alloys as additional materials is presented. The instrumental set-up used in these experiments are described.

Lasers for materials processing: specifications and trends

An overview is given of the types of lasers dominating the field of laser materials processing. The most prominent lasers in this field are the CO2 and the Nd: YAG laser. The domain of CO2 lasers is applications which demand high laser powers (up to 30 kW are available at present), whereas the domain of Nd:YAG lasers is micro-machining applications. In the kilowatt range of laser output power, the two types of lasers are in competition. New diffusion-cooled CO2 laser systems are capable of output laser powers of several kilowatts, with good beam qualities, while still being quite compact. The output power and beam quality of Nd:YAG lasers has been improved in recent years, so that Nd:YAG lasers are now an alternative to CO2 lasers even in the kilowatt range. This is especially true for applications that demand optical fibre transmission of the laser beam, which is possible with Nd:YAG laser light but not with the longerwavelength light emitted by CO2 lasers. The main problem in solid-state lasers such as Nd:YAG is the thermal lensing effect and damage due to thermal stresses. In order to reduce thermal loading, cooling has to be enhanced. Several alternative geometries have been proposed to reduce thermal loading and, by this, thermal lensing effects. There are now slab and tube geometries which allow much higher output powers than the conventionally used laser rods. A very new scheme proposes a thin slab whose cooled side is also used as one of the laser mirrors, so that thermal gradients occur mainly in the direction of the beam propagation and not perpendicular to it, as is the case in the other geometries. As well as CO2 and Nd:YAG lasers, semiconductor laser diodes are very promising for direct use of the emitted light or as pump sources for Nd:YAG and other solid-state lasers. When packaging together thousands of single laser diodes, output powers of several kilowatts can be realized. Major problems are collimation of the highly divergent laser beams and cooling of the laser diode bars.