Solidification and microstructural aspects of laser deposited Ni-Mo-Cr-Si alloy on stainless steel

Abstract

Laser cladding of stainless steel substrate was carried out using Ni-32Mo-15Cr-3Si (wt%) alloy powder. Laser cladding parameters were optimized to obtain defectfree and metallurgically bonded clad. Variation in solidification rate, cooling rate and compositional variation resulted in heterogeneous microstructure. Microstructure was found to be distinctly different in regions of clad cross-section. Majority of the region was found to consist of eutectic of Mo-rich hcp intermetallic Laves phase and NiFe fcc gamma solid solution phases. Extensive microstructural examinations of different clad regions have been carried out using microscopy and microanalysis techniques.