Interfacial reaction in cast WC particulate reinforced titanium metal matrix composites coating produced by laser processing

• Cast WC particulate Ti-MMCs coating was produced by laser injection process.
• Less carbon atoms were released when cast WC was used as reinforcement.
• The reaction product TiC was suppressed and the coating exhibits good ductility.
• The reaction layers are effective in load transfer under an external load.

Laser injection of ceramic particle was conducted to produce particulate reinforced metal matrix composites (MMCs) coating on Ti–6Al–4V alloy. Cast WC particle (WCp) was used as injection reinforcement to avoid excessive release of carbon atoms into the melt pool. The interfaces and boundaries between WC and Ti matrix were investigated by electron microscopy study. Compared with single crystal WCp, cast WCp was an appropriate solution to control the reaction products (TiC) in the matrix and the total amount of reaction products was significantly reduced. Irregular-shape reaction layers were formed around cast WCp. The reaction layers consist of a W2C layer and a mixed layer of W and TiC. Such reaction layers are effective in load transfer under an external load.