Product Code: PIC2008_1207

Laser Melt Injection of Monocrystalline WC Particles into Ti-6Al-4V
Authors:
Dejian Liu, Harbin Institute of Technology; Harbin Peoples Republic of China
Fuquan Li, Harbin Institute of Technology; Harbin Peoples Republic of China
Liqun Li, Harbin Institute of Technology; Harbin Peoples Republic of China
Yanbin Chen, Harbin Institute of Technology; Harbin Peoples Republic of China
Presented at PICALO 2008

The laser melt injection (LMI) process was explored to produce WC particles (WCp) reinforced Ti-6Al-4V metal matrix composites (MMCs). In particular the high strength monocrystalline WC particles was used as injection particles to avoid the intercrystalline cracking often observed in granular or cast WCp reinforced MMCs. During the LMI process, the WCp was injected into the back of the melt pool to prevent WCp from excessive dissolution. Moreover, different parameters were applied, and the processing window of this technique was obtained. The MMCs layers were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the WCp distribute uniformly in the MMCs layer, and the graded WCp distribution in the depth direction of the MMCs layer is found. In addition, some new phases such as TiC and W2C can be observed in the MMCs layer. TiC decrease both in quantity and size with the distance from the surface to the bottom of the MMCs layer. Two reaction layers, namely W2C and TiC layer, are observed in the WC/Ti reaction zone. Moreover, the position of the particle injection plays a critical role in the thickness of the reaction layer.