Improving the wear resistance of white cast iron using a new concept – High-entropy microstructure

This study was conducted with attempt to break through the bottleneck using a new concept – high-entropy microstructure. It has been recently demonstrated that an alloy containing more than five elements with the concentration of each element in the range of 5–35% could have a so-called high-entropy microstructure, which is very fine without large-sized intermetallic phases that reduce the resistance to fracture during high-stress wear and impact wear. In this study, this new concept was applied to modify a white cast iron by adding a few carbide-forming elements to the material simultaneously. The carbide-forming elements mutually competed to form their own carbides and this competition also helped to suppress the growth of the carbides, so that carbide refinement could be achieved. Strong carbide-forming elements, Ti, V, Mo and W, were simultaneously added to Fe–20Cr–5C alloy. As the amount of added elements increased, primary M7C3 in the original white cast iron was eliminated with the formation of various finer carbides, including eutectic M7C3, MC and M6C. Compared to unmodified white cast iron, the modified alloys have demonstrated promising improvement in the wear resistance.