A study on phase transformation and particle distribution during machining titanium metal matrix composites

Metal matrix composites are materials composed of nonmetallic phases distributed in a metallic matrix. They exhibit outstanding combination of preferable properties such as increased strength, low weight, high stiffness, high wear resistance and high elastic modulus. Although the system offers superior properties, the hard and abrasive nature of the reinforcements induces severe issues in the field of machining. Chip morphology and surface integrity analyses are of prime importance to investigate the machinability of MMCs. Influence of elemental analysis of chip in chip morphology and phase analysis on surface integrity is covered in this research. In this study elemental analysis has been conducted to reveal the distribution of particles in the matrix, in the raw material and chips generated under different cutting conditions. The effect of particle accumulation on chip edge serration has been investigated. Also the mechanism of particle fracture and debonding and influence of feed rate on the particle debonding is studied. In order to study the role of thermal effect on the generation of machining residual stress, X-ray diffraction analysis (XRD) is utilized, and the possibility of phase transformation is investigated.