Abstract:
The WC‒Cu‒10Ni‒5Mn‒3Sn cemented carbide doped with Cr
3C
2 was prepared by pressureless melt infiltration at
1210 ℃ for 1.5 h, the effect of Cr
3C
2 dopant (0.0, 0.2%, 0.4%, 0.6%, 0.8%, and 1.0%, mass fraction) on the microstructure and mechanical properties of the WC‒Cu‒10Ni‒5Mn‒3Sn alloys was investigated. The results show that during the infiltration process, the WC particles partially decompose with the addition of Cr
3C
2, the Ni
2W
4C and Cr
7C
3 appear in the alloys, and the (W,Cr)C
x and (Cr,W)C are formed from Cr
7C
3 and W produced by the decomposition of WC. The emergence of new phases causes the change in WC grain size, thereby altering the mechanical properties of the alloys. With the mass fraction increase of Cr
3C
2, the hardness and flexural strength show the trend of first increasing and then decreasing. When the mass fraction of Cr
3C
2 is 0.4% and 0.6%, respectively, the hardness and flexural strength reach the maximum, which is HRA 93.1 and
1720 MPa, respectively. The addition of Cr
3C
2 is not conducive to the impact toughness, the alloys without Cr
3C
2 have the highest impact toughness as 4.65 J·cm
‒2.