Wettability and solubility behavior of Fe–B–C binder on (Cr–Ti–C)-reinforced composites

Abstract

Iron-base matrix composites containing Cr-20Ti-10C reinforcement fabricated by infiltrating at 1200°C to 1280°C for 30 to 60 mins are investigated in this work. Peculiarities of the formation of the interfaces between Cr-20Ti-10C hard alloy and Fe-3.1B-0.1C liquid alloy (wt. pct) are determined. It includes the study of the solubility between the iron-base binder and the reinforcement combined with the investigation of the contact angles of the liquid phase formed at infiltration temperature by sessile drop method. X-ray analysis as well as optical and scanning electron microscopy is employed to investigate the binder/particulate interfaces. The interfacial zones produced as a result of contact interaction consist of (Cr,Ti)₇C₃ and (Ti,Cr)₃C phases embedded in α-Fe₃(C,B) eutectic alloyed with Cr and Ti. The origin of the formation of the interfaces is probably related to the partial dissolution of the low-melting-temperature particulate phase identified as (Cr,Ti)₇C₃ in the molten Fe–B–C binder. When raising the infiltrating temperature and prolonging the infiltrating period, wetting properties of Cr-20Ti-10C improve. This fact opens the possibility to replace copper-base alloys as binder by a cheaper and stronger iron-base alloy.