Critical aspects for an efficient assessment of novel materials design

Abstract

Finding a replacement for WC-Co hardmetals has been investigated for several years. The design space is rather limited when considering WC as hardphase, because most transition metals form detrimental interconnected-carbides when added above their solubility limit, which is in most cases rather low. However, the peculiar characteristics of WC make worthwhile the effort, as no other hardphase provides such an outstanding combination properties: hardness/toughness ratio, electrical and thermal conductivity, etc. This paper illustrates with some examples how the design space can be efficiently studied when some critical aspects are tackled during the design. For instance, features such as solubility limits in the binder, the size of the carbon window or the dramatic changes in the binder composition at different carbon activities can be tuned differently depending on the binder chemistry Thermodynamic software packages provide a very powerful tool to speed up the design of novel alternatives, and their further development might be the key to facilitate the discovery of new material combinations to cover not only current needs but also future ones