W–Ni–Fe Refractory Alloy Sintered by Hot Oscillating Pressure Under Different Amplitudes

Abstract

Hot oscillating pressure (HOP) at different amplitudes (0, 5, and 10 MPa) is used to create a tungsten refractory alloy with narrow grain size distribution, higher hardness, and excellent corrosion resistance. The relative density and properties of sintered alloys are significantly improved and enhanced through the amplitude applied. The highest relative density about 99.2% with the narrowest average thickness bonding phase is presented in 10 MPa amplitude alloy. And its average grain size is only 3.67 μm, with a grain growth rate that is only 1.12 × 10−15 m2s−1 slower than that without the amplitude alloy (0 MPa amplitude alloy). Then the excellent hardness (454.7 HV0.5) is obtained. More importantly, the corrosion current of 10 MPa amplitude alloy is only just 5.09 × 10−6 A cm−2 and reduces by nearly 9% compared with 0 MPa amplitude alloy. The hardness and corrosion resistance are better than those of other similar materials ever reported. The above results show that the HOP with amplitudes has a positive effect on improving the densification, hardness, corrosion resistance, and inhibiting the growth of grain size.