Ionic Liquid-Assisted Preparation of Ni-Cr Dual Wrapped ZTA Particles for Reinforced Iron-Based Composites

The surface metallization of ZTA particles with Ni-Cr coatings is performed to enhance the wettability of ZTA reinforced high manganese steel (HMS) matrix composites. Well-proportioned and continuous Ni-Cr coated ZTA particles (ZTA(p)@Ni-Cr) are prepared by choline chloride-ethylene glycol (ChCl-EG) ionic liquid-assisted electroless plating method. The Ni(CH3COO)(2)-containing activator is used in the pretreatment process and the effects of CrCl3 concentration, ChCl-EG concentration, temperature, ZTA concentration, and deposition times on the plating process are investigated systematically. The results show that the formation of Ni active sites on ZTA surface by Ni(CH3COO)(2) activation pretreatment can efficiently simplify operation and lower cost compared with the SnCl2 sensitization-AgNO3 activation method. By controlling experimental condition, uniform Ni-Cr layers with a thickness of 7.96-30.84 mu m can be obtained and the Cr element content is about 6.31 at%. Additionally, ZTA(p)@Ni-Cr reinforced HMS matrix composite are fabricated without crack, shrink, and pore at the interface by non-pressure casting infiltration method. The formation of an interface layer about 17.61 mu m and the diffusion of element Ni and Cr between ZTA phase and HMS matrix can greatly reinforce the interfacial bonding strength of the ZTA(p)@Ni-Cr reinforced HMS matrix composite.