Influence of the vacuum hot pressing process on the microstructure, mechanical properties, and material characteristics of CrCoNiTa3 alloys

This research fabricates CrCoNiTa 3 alloys using the vacuum hot pressing process, where micron grade chromium (6 μm), cobalt (3 μm), nickel (3 μm) and tantalum (25 μm) powders are mixed by means of ball milling. The experiments utilize various hot pressing temperatures (1000, 1050, 1100, and 1150 °C) and hot pressing pressures (20, 35 and 50 MPa) to determine the optimal hot pressing parameters for CrCoNiTa 3 alloys, while simultaneously investigating the differences in microstructures and material characteristics. The results show that the optimal hot pressing parameters of this alloy were 1100 °C at 20 MPa for 1 h. The sintering density was enhanced to 8.34 g cm −3 , and the hardness and transverse rupture strength (TRS) reached 72.9 HRA and 2266.1 MPa, respectively. Meanwhile, the electrical conductivity was 1.46 × 10 3 S cm −1 and the polarization resistance was 1309.1 Ω cm 2 . Furthermore, the EBSD results confirm that the FCC solid solution and twin of the CrCoNiTa 3 crystalline structure, and no preferred grain orientation was found. • CrCoNiTa 3 alloys had the highest TRS value (2266.1 MPa) after 1100 °C, 20 MPa for 1 h. • CrCoNiTa 3 alloys obtained the highest hardness (72.9 HRA) after an optimal procedure. • EBSD results confirm the FCC solid solution and twin of the CrCoNiTa 3 structures. • The mean grain size of the FCC solid solution of CrCoNiTa 3 is about 572 nm. • For the <111> crystal orientation family, the angle between the crystal grains is about 60°.