等离子烧结温度对CoCrCuFeNi高熵合金组织及性能的影响

CoCrCuFeNi high-entropy alloy was successfully fabricated by spark plasma sintering (SPS) at 900, 1000, 1100 and 1150℃. The tensile at room temperature results show that the tensile strength of the CoCrCuFeNi alloy firstly increases and then decreases with the increase of sintering temperature. However, the uniform elongation firstly significantly increases and then decreases. When the sintering is carried out at 1100℃, the yield strength and ultimate tensile strength of CoCrCuFeNi alloy reach 379.3 and 655.6 MPa, respectively, and the elongation after fracture is 21.9%. When sintering temperature exceeds 1100℃, the element segregation obviously appears in the material because of the local melting. Besides, the tensile fracture is brittle feature along the surface of the spherical powder at 900℃.While the fracture is ductile fracture as the sintering temperature increases. Because of the diffusion of carbon atom during high temperature sintering, TEM results show that the carbon reacts with the matrix to form the second phase carbide particles inside the matrix.