Investigations into the Microstructure and Dry Sliding Wear Behavior of a Hybrid Ti6Al4V-BN-B <sub>4</sub>C Metal Matrix Composites

Abstract

A unique combination of mechanical properties and good thermal conductivity could result in an improved hardness, resistance to wear of fabricated hybrid Ti6Al4V metal matrix composite systems. Properties of Ti6Al4V alloy can be enhanced by applying the coatings of Boron Nitride (BN), Boron carbide (BC) and Ti6Al4V alloy particles on a Ti6Al4V alloy substrate using a Laser metal deposition system. This paper reports an investigation of a new fabricated hybrid metal matrix composite system (Ti6Al4V-BN-B4C). Microstructure, Hardness property and wears resistance of Ti6Al4V alloy Metal Matrix composite coatings were investigated and extensively reported. Good hardness property, Superior wear resistance of metal matrix composite systems, however, improves the poor tribology of Ti6Al4V alloy. Laser Metal Deposition technique using 3 kW Nd: YAG laser power was used to deposit particle coatings on the TiAl4V alloy substrate. Their resultant microstructure revealed an excellent bonding strength and homogeneously distributed BN-B4C particle and Ti6Al4V alloy particles free from cracks and pores. 50% overlapping multiple coating tracks or layers were cut to specification for microhardness examination. The primary contribution of this research to understanding the wear of materials was established by carrying out dry sliding wear experiment of each sample under applied load of 15 N and 25 N. Wear experiment was conducted using the dry sliding technique and was carried out under dry sliding conditions of 2 mm stroke length at room temperature and WC ball counterbody was used. Wear resistance of the hybrid metal matrix composite improved considerably, signifying good distribution of ceramic particles formed as observed by SEM and X-ray diffraction spectrum.