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

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.