Microstructure and wear resistance of laser clad TiB-TiC/TiNi-Ti2Ni intermetallic coating on titanium alloy
(1. School of Materials Science and Engineering, Beihang University, Beijing 100191, China;
2. Engineering Research Center of Ministry of Education on Laser Direct Manufacturing for
Large Metallic Components, Beihang University, Beijing 100191, China)
2. Engineering Research Center of Ministry of Education on Laser Direct Manufacturing for
Large Metallic Components, Beihang University, Beijing 100191, China)
Abstract: A wear resistant TiB-TiC reinforced TiNi-Ti2Ni intermetallic matrix composite coating (TiB-TiC/TiNi-Ti2Ni) was prepared on Ti-6.5Al-2Zr-1Mo-1V titanium alloy by the laser cladding process using Ti+Ni+B4C powder blends as the precursor materials. Microstructure and worn surface morphologies of the coating were characterized by optical microscopy (OM), scan electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDS) and atomic force microscopy (AFM). Wear resistance of the coating was evaluated under dry sliding wear test condition at room temperature. The results indicate that the laser clad coating has a unique microstructure composed of flower-like TiB-TiC eutectic ceramics uniformly distributed in the TiNi-Ti2Ni dual-phase intermetallic matrix. The coating exhibits an excellent wear resistance because of combined action of hard TiB-TiC eutectic ceramic reinforcements and ductile TiNi-Ti2Ni dual-phase intermetallic matrix.
Key words: intermetallic; composite; coating; laser cladding; wear