Microstructure, wear and corrosion properties of B–C composite layers on pure titanium

Abstract

In this work, TA2 pure titanium was treated by borocarburizing (BC), boriding first and then carburizing (B + C), and carburizing first and then boriding (C + B), and morphology and wear and corrosion properties of these layers were investigated. The results show that the BC layer and B + C layer are composed of TiB, TiB2, and TiC phases, while the C + B layer consists of TiC and TiB2 phases. The wear type of these treated samples is abrasive wear, and wear resistance is in the sequence of B + C layer > BC layer > C + B layer. In 3.5 wt.% NaCl solution, corrosion resistance is in the order of B + C layer > C + B layer > BC layer > TA2. In 5.0 vol.% H2SO4 solution, corrosion resistance is in the order of C + B layer > B + C layer > BC layer > TA2. The B + C treatment can form a layer with gentle hardness gradient, excellent wear properties, and good corrosion resistance, which is most conducive to the bonding between layer and matrix.