Microstructure, mechanical properties and wear resistance of TiNbCrMo[formula omitted] refractory multi-principal element alloys

Abstract

The advancement of refractory multi-principal element alloys, exhibiting superior mechanical properties and wear resistance, is of paramount importance in materials engineering. This study introduces a novel series of refractory multi-principal element alloys, designated as TiNbCrMox (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0), and methodically explores the impact of varying molybdenum (Mo) content on their microstructural characteristics, phase composition, mechanical performance, and wear resistance. Empirical analyses reveal that these alloys are primarily composed of body-centered cubic (BCC) and Laves phases. The yield strength at ambient temperature is observed to span a range from 1572.8 MPa to 1902.5 MPa. Notably, the strategic addition of Mo in controlled proportions has been found to significantly enhance the hardness and ductility of the TiNbCrMox alloys. This improvement is attributed to the modification in the Laves phase concentration and the degree of lattice distortion. Moreover, the study identifies a marked increase in the hardness of the alloys, which, in conjunction with the formation of a lubricative oxide film, substantially reduces their wear rate. Specifically, the TiNbCrMo0.6 variant demonstrates a notably low wear rate, measured at 9.05 × 10−5 mm3/(N m). This investigation offers invaluable insights into the design and development of high-strength, wear-resistant metallic materials, highlighting their potential for diverse industrial applications.