Study on the FeCoCrNiMnTix High Entropy Alloys Fabricated by Laser Cladding

Abstract

Because of the high entropy effect, a simple solid solution structure can be obtained in high entropy alloys (HEAs), giving the HEAs greater overall properties than conventional alloys. Cladding layers of FeCoCrNiMnTix HEAs were prepared on Q355 steel by laser cladding technology. X-ray diffraction (XRD), metallographic microscope (OM), and scanning electron microscope (SEM) were used to examine the microstructure of the cladding layers. The microhardness and wear resistance were tested using a Vickers microhardness tester and wear testing machine, respectively. The FeCoCrNiMn HEAs consisted of a face-centered cubic (FCC) solid solution. The addition of Ti promoted the formation of body-centered cubic (BCC) and hexagonal solid solution. When Ti content was higher than x=0.8, the Laves phase formed. The addition of Ti increased the microhardness of the FeCoCrNiMnTix (x=0.5, 0.6, 0.8, 1.0) HEAs, which is due to the effect of solution strengthening, microstructure strengthening, and grain refinement. When Ti content was less than x=0.6, the alloy’s wear resistance was positively correlated with its hardness, and the Ti0.6 alloy had the best wear resistance. However, as Ti content exceeded x=0.6, the brittle and hard Laves phase formed, which resulted in reduced wear resistance.