Effect of Cryogenic Treatment on Thermal Behavior of WC-9Ni-xCeO2 Cemented Carbides

Abstract

A series of specimens of WC-9Ni-xCeO2 cemented carbides were prepared. The influences of CeO2 addition and cryogenic treatment (CT) on thermal conductivity, thermal diffusion coefficient, and heat capacity of the alloys were investigated using a Hot Disk thermal constant analyzer, a X-ray diffractometer (XRD), and a scanning electron microscope (SEM) coupled with an energy dispersive X-ray detector (EDS). The results indicated that with the increase in CeO2 content in WC-9Ni-xCeO2 cemented carbides, the thermal conductivity and thermal diffusion coefficient first increase and then decrease. The change in heat capacity of the cemented carbides, however, does not show obvious regularity. CT tends to increase the thermal conductivity, thermal diffusion coefficient, and decrease the heat capacity of WC-9Ni-xCeO2 cemented carbides. Notably, the degree of influence of CT on thermal properties of the cemented carbides with various CeO2 contents is obviously different. After CT, with an increase in the CeO2 content, the variation of amplitude of thermal conductivity decreases. Similar situations also appear in the other two kinds of thermal properties.