Mitigation of Machining Challenges in Non-traditional Machinings (NTMs) with Metal Matrix Composites (MMCs)

Metal matrix composites (MMCs) offer advantages over pure matrix materials, such as higher tensile strength, improved stiffness, hardness, corrosion resistance, and wear resistance. However, MMCs often have non-uniform structures with uneven reinforcement distribution, creating significant machining challenges. These include fiber pull-out, excessive tool wear due to reinforcement hardness, and matrix cracking. This chapter discusses strategies to address these challenges, focusing on non-traditional machining processes. It highlights that fatigue life in machining is influenced by the size of reinforcement particles, while surface configuration is affected by intermediate phase formation. Surface integrity is critical to machinability, with processes like electro-discharge machining (EDM) causing thermal degradation and resolidified layer deposition on the surface. Powder mixed EDM (PMEDM) is introduced to mitigate these issues. In laser beam machining, matrix microstructure transformation impacts material properties. In conventional machining, polycrystalline and diamond-coated tools are preferred for reduced wear. Blasting erosion arc machining is gaining traction for enhancing MMC machinability.