Synthesis and Characterization Study of Al10Cr25Co20Ni25Fe20 High-Entropy Alloy Powders through Mechanical Alloying

Al10Cr25Co20Ni25Fe20 high-entropy alloys (HEA) with ultrafine grains was synthesized through 30 h of mechanical alloying (MA). The morphological study of prepared high-entropy alloy powders was done by using scanning electron microscope images. Crystallite size and lattice strain of prepared high-entropy alloy were investigated through x-ray diffraction technique. Consolidation and sintering of HEA powders done by two methods such as conventional sintering and spark plasma sintering methods at 1000 degrees and 1200 degrees C. After 30 h of MA, crystallite size 44 nm and lattice strain 0.182 was obtained. The mechanical properties analysis of high-entropy alloy was done in terms of its density, hardness measurements and compression test. For conventional sintering, the hardness values of 135 +/- 6 HV0.5 for 1000 degrees C and 186 +/- 8 HV0.5 for 1200 degrees C were obtained. For spark plasma sintering, the hardness values of 167 +/- 5 HV0.5 for 1000 degrees C and 212 +/- 6 HV0.5 for 1200 degrees C was obtained(.) Ultimate compressive strength for conventional sintering at 1000 degrees C and 1200 degrees C was 246 +/- 5 MPa and 305 +/- 6 MPa. Ultimate compressive strength of HEA for spark plasma sintered composite at 1000 degrees C and 1200 degrees C was 369 +/- 5 MPa and 442 +/- 5 MPa and the total elongation was 17.7%. BCC and FCC biphase mixture was obtained and confirmed by transmission electron microscopy images and electron backscattered diffraction analysis.