Executive Summary : | The technology pertaining to laser-based 3D printing of metallic parts has advanced significantly over the last few decades particularly in terms of different types of metals which can be processed, the complexity of the parts as well as the functional and mechanical properties of the built parts. In spite of that, major impedance still remains in its mass adoption in the industry which is mainly due to its low throughput compared to traditional manufacturing technologies. This has, in turn, also led to higher production costs per unit. Novel approaches are thus necessary to improve the production rate or throughput of laser-based 3D printing process. Laser beam shaping and splitting are some of the versatile methods which can dramatically increase the processing rate. In these techniques, optical elements are used either to split the incoming laser beam into multiple parts for parallel processing or to transform the laser beam into arbitrary user defined shapes for a single exposure processing. This will allow to scale up the laser processing method from a single point by point mode to a multiple points mode or a large area mode. This proposal will aim to develop an indigenous multi beam and imaging-based metal 3D printing setup centered on laser powder bed fusion using appropriate laser beam shaping. While simultaneous multi point or large area laser processing could be challenging for sintering high melting point metals due to the high energy requirement, this will be mitigated by the use of metallic nano powders which has significantly lower energy requirement for their sintering. Along with the setup design, its capabilities for processing metallic parts in the mesoscale, ranging from tens of microns to tens of millimeters will be developed. Besides, appropriate beam shaping can significantly influence the mechanical and microstructural properties by precisely controlling the spatial energy input in the material. Numerical investigation through simulation models due to the multiple and complex laser beam processing will be another aspect of this work. This will lead to a fundamental physical understanding of laser material interaction combined with aspects of optical system design. In the future, this work will pave the way for the development of micro additive manufacturing techniques and successful development of such technology will be of great interest to commercial entities. |