Characterisation of TiC–NiMo reinforced Ni-based hardfacing

Abstract

In the present study, TiC–NiMo composites were remilled to particle size of 250–315μm and used as reinforcements for NiCrBSi alloy by plasma transferred arc hardfacing process. The manufactured hardfacing alloy was characterised in terms of microstructure, mechanical properties and abrasive wear resistance. Deposition results indicate good quality thick coating with uniform distribution of hard cermet (TiC–NiMo) particles in the matrix, minimum level of hard particle dissolution and low porosity of the hardfacing. Cermet particles remain in initial form and consist of agglomerates (TiC and (Ti,Mo)C grains) embedded into Ni-based matrix. The mechanical properties of the TiC and (Ti,Mo)C phases measured by nanoindentation are very similar exhibiting a narrow distribution. The nano-scratching test reveals excellent bonding between the matrix and cermets in the hardfacing. No crack propagation was found in the interface matrix/hard phase region.The abrasive wear results ensure the promising features of TiC–NiMo reinforcements for Ni-based alloys. Produced coatings showed excellent performance under high-stress abrasion with wear values lower than for industrially used WC/W2C reinforced coatings.