Wetting of FeCoCrNiTi0.2 high entropy alloy on the (HfZrTiTaNb)C high entropy ceramic

Abstract

To clarify the unique interfacial interaction of heterogeneous system under high entropy effect, the wettability of the liquid FeCoCrNiTi0.2 high entropy alloy (HEA) on the (HfZrTiTaNb)C high entropy ceramic (HEC) was studied at 1370–1430 °C. The dissolved HEC contributed Hf and Zr atoms to the liquid HEA, and their adsorption at the triple line promoted the rapid reduction of the initial contact angle. Meanwhile, the active Ti in liquid HEA diffused into the HEC, which induced a phase transition from HEC to HEC' with the unaltered lattice structure. The spreading of liquid HEA depended on the formation of HEC' judged by the linear relationship between ln(cosθe−cosθd) and time. The calculated high wetting activation energies revealed sluggish spreading for the HEA/HEC system. Based on the good wettability of HEA/HEC system, the HEC brazed joints with high shear strengths above 245 MPa were constructed using HEA fillers at a wide temperature interval of 1400–1490 °C.