A study on Porosity in Micro-Selective Laser Sintering of Copper Powder

Abstract

In Selective Laser Sintering metal powder particles are consolidated layer-by-layer through laser heating. In recent years, process has been improved that addressed the defects such as porosity, micro-cracks etc., resulting its wider applications in industries. However, there is a promising opportunity exists to use this process in micro manufacturing, which has not been exploited to a great extent. In this work, an attempt has been made to understand the porosity defects formed in micro-selective laser sintering (Micro-Sintering) of copper powder. Molecular Dynamics based simulation study performed for the Micro-Sintering of nano-scale powders has shown insight into the mechanism of neck growth formation and resulting porosity on their joining with adjacent particles. The other defects such as cracks formation, balling effects, presence of residual binders contributing to porosity and micro-cracks observed during experimental study on Micro-Sintering of 5μm copper powder has also been discussed.