Comparative analysis of micrometric and nano-metric WC-10Co-4Cr GTA cladding

Abstract

The present research work examines the wear performance and cost of developing the micrometric and nano-metric WC-10Co-4Cr GTA claddings. Both the claddings were developed at optimized parametric conditions by using a fully automatic GTA welding machine. The microstructure, elemental compositions and phases present in the deposited claddings were characterized by using FE-SEM, EDS and XRD, respectively. Micro-hardness of the micrometric and nano-metric claddings were evaluated with the help of a Vickers hardness tester. A pin-on-disc tribometer was used for conducting the abrasive wear test. The experimental results revealed that the abrasive wear in nano-metric cladding reduces by 30.72% compared to micrometric cladding. The average microhardness of nano-metric cladding has improved by 25.51% than micrometric cladding. Microstructural examination of worn-out claddings shows that the material was removed from the claddings due to the eruption of CoCr binder matrix along with the pull-out of WC grains, caused by the sliding motion of SiC particles. However, the cost of fabricating nano-metric cladding per unit area (Rs 0.163 mm−2) was higher than the micrometric cladding (Rs 0.107 mm−2) owing to the higher material cost of nano-WC-10Co-4Cr powder.