ABSTRACT

Laser-assisted machining (LAM) represents an important and growing eld in the area of thermally assisted machining (TAM), also known historically as hot machining. LAM is a hybrid machining process that integrates a laser source into a conventional machining setting. Lasers are used to elevate the workpiece temperature at the cutting zone to facilitate the material removal process by a cutting tool. LAM excludes those thermal machining processes in which the heating source is the same as the “cutting tool,” such as the laser in laser cutting and the plasma in plasma cutting. Also excluded are such machining processes in which heat generation is intrinsic (e.g., due to plastic deformation at the shear zone). The purpose of heating in LAM is to reduce the hardness and shear strength of the workpiece material as well as to improve ductility in case of hard and brittle materials, and to assist the cutting tool in the material removal process. Ideally, only the material

20.1 Introduction .......................................................................................................................... 537 20.2 Laser-Assisted Machining of Structural Ceramics .............................................................. 539

20.2.1 Material Removal Mechanism .................................................................................. 539 20.2.2 Machinability-Cutting Force, Tool Wear, and Material Removal Rate ................ 541 20.2.3 Surface Integrity-Surface Roughness, Microstructure, Surface Damage,

and Residual Stress ................................................................................................... 543 20.2.4 Theoretical/Numerical Modeling ............................................................................. 545

20.2.4.1 Thermal Modeling ..................................................................................... 545 20.2.4.2 Thermo-Mechanical Modeling ..................................................................546