Influence of elliptical particle inclination on the formation mechanism of surface defects in turning PTMCs

In order to investigate the influence of reinforcing particles on the machining process and the machined surface, a single-particle turning simulation of particle-reinforced titanium matrix composites (PTMCs) is carried out in this paper. The hard reinforcing phase in the particle-reinforced titanium matrix composites was simplified into elliptical particles, and the machining process and surface under various tilt angles were investigated. The effect of TiC particles with different inclination angles on the formation of pits on the machined surface was investigated and a comparative test was conducted to demonstrate the mechanism of surface crater formation. The results show that the surface quality of the processing is strongly influenced by the inclination angle of the reinforcing particles. When the tool cutting path is located in the center of the elliptical particle, the main axis of the elliptical particle is closer to the X -axis, and the particle fragmentation is more serious and the machined surface quality is worse. As the spindle of the elliptical particle gets closer to the Y -axis, the machined surface quality improves significantly. The breakage mechanism of hard TiC particles during PTMCs was analyzed. The interaction mechanism between the actual breaking process and the variation of cutting force was revealed. When the peak value of cutting force is higher, the state of particle breakage in the substrate becomes more severe. The result of this work has important implications for the subsequent suppression of surface defects and improvement of the machined surface quality.