Laser metal deposition for powder metallurgy parts

By combining laser and powder processing, laser metal deposition (LMD) enables the manufacture of high precision near-net shape components from powders, so enhancing materials utilisation. Rapid prototyping, in situ repair and surfacing are among the capabilities of LMD; applications cover the medical, defence and aerospace sectors, with potential applications in oil and gas and other sectors. To take full advantage of the rapid fabrication of complex geometries and automated repair offered by LMD, there is a need to develop understanding of the process–microstructure–property relationships, particularly the effect of powder characteristics on process variables and on the metallurgy and resulting mechanical properties. A brief overview of LMD from a PM perspective is presented, with an emphasis on underlying mechanisms and attendant metallurgical issues. Recent developments in the state-of-the-art are discussed and potential applications combining PM and LMD are identified.