Effects of mechanical alloying and pulse electric sintering processing parameters on Ti20Al20Cr5Nb5Ni17Cu16Co17 high entropy alloys by response surface methodology

Abstract

Impact of milling and sintering processes on the relative density (RD) and microhardness (MH) were investigated on TiAl-based (Ti₂₀Al₂₀Cr₅Nb₅Ni₁₇Cu₁₆Co₁₇) high entropy alloys (HEAs) fabricated from pulse electric sintering (PES) process at a constant heating rate (100 °C/min), 5 min dwell-time, and pressure of 50 MPa. A predictive model was created using response surface methodology (RSM) to analyze the impact of sintering temperature and milling time on the process. To minimize the number of experimental trials, uniform-design (UDD) of the RSM was employed in the design of the experiment, hence eliminating the need for a trial-and-error approach often connected with traditional experimental techniques. Observation shows that both milling time and sintering temperature played a crucial role in producing a high level of densification, resulting in improved mechanical characteristics. The optimization model indicates that with 9.7 h milling time and 887.9 °C sintering temperature, it is possible to achieve acceptable outcomes including a 99.72 % RD, porosity percentage of 0.28 %, and MH value of 802.9 HV.