Cutting forces and TEM analysis of the generated surface during machining metal matrix composites

Cutting of metal matrix composites (MMCs) has been considerably difficult due to the extremely abrasive nature of the reinforcements that causes rapid tool wear and high machining cost. An investigation was carried out to clearly understand the role played by the ductile matrix on the machining performance based on the estimation of line defects generated as a result of cutting. The microstructural studies were conducted using transmission electron microscopy (TEM) on the machined surface to reveal the deformation pattern of the work hardening matrix and its correlation with the forces generated during turning MMCs. Cracking and debonding of the reinforcement particles are the significant damage modes that directly affect the tool performance. It was found that the particle size and volume fraction affect the extent of deformation in the generated surface. Also the machining forces are correlated to the plastic deformation characteristics of the matrix material. This investigation provided valuable information on the deformation behaviour of particulate reinforced composites that can improve the performance and accuracy of machining MMCs.