Diffusion kinetics and boronizing of high entropy alloy produced by TIG melting reverse suction method

Abstract

ABSTRACT In this study, CrMnFeCoNi high entropy alloy was produced using TIG melting reverse vacuum method using a shielding gas atmosphere. Produced samples were boronized with pack boriding method at 1173, 1223, 1273 K temperatures and for 2, 4 and 6 h. As a result of the experiments, the morphology of the boride layers formed on the high entropy alloy surfaces was investigated by SEM microscope. The hardness values were measured with a microhardness device and the phases formed on the boride layer were determined by the XRD method. In addition, the thickness and growth kinetics of the boride layer on the high entropy alloy were investigated. The boride coating thickness ranges from 38 µm to 268 µm. FCC crystal structure is present in the HEAs produced in XRD examinations and the hardness value was determined as 242 HV0,05 (± 15). B-dependent phases of Cr, Mn, Fe, Co, Ni were obtained in the coating layer and the hardness value was measured as 2250 HV0,05 maximum. The boride layer activation energy value of the coated HEA was calculated as 376,465 kJ/mol.