Weldability and Microstructure of Nickel-Silicon Based Alloy


The NiSix based alloy typically has poor weldability due to its lower ductility. A limited amount of work has been performed on the weldability of NiSix based alloys. Therefore, the effect of heat treatment and welding parameters on weldability of the alloys, and the relationship between the weldability and microstructure were studied. The results show that the as-cast Ni-Si-Nb-B alloy (Ni 76.5%, Si 20%, Nb 3%, and B 0.5%) could be successfully welded after preheating at 600 °C. The welding procedure should be performed on the alloys before any heat treatment and a preheating at 600 °C should be used. The fusion zone is harder than the matrix due to a large amount of γ phase and a finer microstructure. The cracks are predominantly intergranular in heat affected zone and associated with the needle-like γ phase. The heat treatment before welding increases the tendency of cracking in the fusion zone.


Materials Science and Engineering

Keywords and Phrases

Heat Affected Zone; Heat Treatment; Ni3Si Based Alloy; Weldability

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


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© 2006 Elsevier, All rights reserved.

Publication Date

01 May 2006