Abrasion and toughness property maps for WC/Co hardmetals

Abstract

WC/Co hardmetals are generally designed for applications where resistance to wear, particularly abrasion or erosion, needs to be high but without the low toughness often found in very hard materials. Consequently, mapping the relation between wear characteristics and toughness is fundamental to the process of grade selection in commercial hardmetals. In current research at NPL wear resistance has been assessed using the ASTM B611 abrasion test method and toughness through Palmqvist fracture toughness. Both these tests are now well understood, especially the uncertainties associated with the measurements. Both of the two main types of property map are considered: those concerned with properties associated with end use, e.g. abrasion and toughness; and those concerned with relating microstructural parameters to the property of interest i.e. abrasion and its dependence on WC grain size. Comments are made on the effects of WC grain size distribution and mean grain size.