Analysis of Microstructure and Properties of Cemented Carbide and Invar Alloy Weldment

摘要

Multi-phase composite microstructure was designed in a Ni_(42)C_(0.6)Mn_(3.5)Nb_3Fe_(50.9) invar alloy which was welded to WC-Co cemented carbide. The multi-component composition (Ni_(42)C_(0.6)Mn_(3.5)Nb_3Fe_(50.9)) was chosen such that on welding of the cemented carbide to invar alloy the nonequilibrium interface reactions were suppressed. The microstructures of Ni_(42)C_(0.6)Mn_(3.5)Nb_3Fe_(50.9) invar alloy and the dissimilar materials (WC-Co and Ni_(42)C_(0.6)Mn_(3.5)Nb_3Fe_(50.9)) welded joint were characterized with SEM and EDS analysis, and phase was done using X-rays diffractometer. The hardness profile is determined using micro-hardness measurements. Sound metallurgical bond and smooth hardness transition from 420HV_(0.2) to 870HV_(0.2) near interface were obtained without groove and filler materials.