Stefan Oliver Czerner

Direct micro laser cladding with microscale nanophased powders

A manufacturing method is presented which is based on a very advanced small scale laser cladding technology and which is able to form solid metallic objects being composed of nanophased powders. New developments in powder feeding will be illustrated which can feed microparticles using a combination of brush feeder and ultrasonic vibration. Per layer two materials can be selected. A process chamber and an integrated observation microscope are presented. Full automation is assured using specially designed software and based on industrial standards of PXI technology. Agglomerated nano-phased systems were developed to respond to the needs of microfabrication in terms of phase sets, particle sizes and shapes. Focusing of the particles is realized using a coaxial nozzle. Experimental investigations confirm the high potential of this method through which can generate cladded layers smaller than 15 µm.A manufacturing method is presented which is based on a very advanced small scale laser cladding technology and which is able to form solid metallic objects being composed of nanophased powders. New developments in powder feeding will be illustrated which can feed microparticles using a combination of brush feeder and ultrasonic vibration. Per layer two materials can be selected. A process chamber and an integrated observation microscope are presented. Full automation is assured using specially designed software and based on industrial standards of PXI technology. Agglomerated nano-phased systems were developed to respond to the needs of microfabrication in terms of phase sets, particle sizes and shapes. Focusing of the particles is realized using a coaxial nozzle. Experimental investigations confirm the high potential of this method through which can generate cladded layers smaller than 15 µm.

Micro laser sintering (microls) for rapid prototyping of metal-ceramics

The world market for micro system technology is constantly raising the technical demands for the production of metallic tools and functional parts.With a view to product development rapid prototyping production (RP) methods are one of the most essential instruments of component manufacturing. In particular the macroscopic 3D laser beam processing technologies have proved their high potential with regard to flexible manufacturing of metallic components.The development of new beam sources is giving new abilities of using the RP methods for the production of micro components. Hence, the subject of the present work is the development of a system concept for 3D micro cladding and/or sintering. This system has been qualified by mathematical calculation and experimental investigations. The developed, fully automatically manageable facility contains a Yb:YAG fiber laser with a laser beam focus diameter below 10 µm. For closed loop quality control, pyrometric temperature sensoric has been integrated into the facility. The temperature on the melt pool surface is controlled with the help of a focusable measuring spot down to 50 µm. The process takes place in a controlled protection gas chamber in which atmospheres with an oxygen content below 100 ppm can be guaranteed. The micro particles are feeded aerodynamically. The concentrated delivery of the powders to the melt pool is realized by a focusing coaxial nozzle.Experimental investigations confirm the high potential of this method for the production of sintered layers smaller than 15 µm.The world market for micro system technology is constantly raising the technical demands for the production of metallic tools and functional parts.With a view to product development rapid prototyping production (RP) methods are one of the most essential instruments of component manufacturing. In particular the macroscopic 3D laser beam processing technologies have proved their high potential with regard to flexible manufacturing of metallic components.The development of new beam sources is giving new abilities of using the RP methods for the production of micro components. Hence, the subject of the present work is the development of a system concept for 3D micro cladding and/or sintering. This system has been qualified by mathematical calculation and experimental investigations. The developed, fully automatically manageable facility contains a Yb:YAG fiber laser with a laser beam focus diameter below 10 µm. For closed loop quality control, pyrometric temperature sensoric has been integrated into the facil...