Laser Cutting of the TiN +Al \u3c inf\u3e 2 O \u3c inf\u3e 3 Reinforced Aluminium Matrix Composites Through Semisolid Sintering

Laser cutting is commonly used for manufacturing of strong composites as an advance machining process. It is suitable for geometrically complex profile cutting in the metals used in manufacturing engineering. In the present work, laser cutting process of aluminium matrix composites obtained from scrap chips reinforced with hard ceramics (TiN + Al2O3) were carried out. They are being widely used in the aerospace and automobile industries such as aircraft structure, internal combustion engines, plain bearings, wheels, pistons, brake rotors for high speed trains, etc. In fact, TiN does not react with aluminium. It keeps its thermal stability up to 3000 °C and chemically inert to most of the common acids. It is industrially important due to its high hardness, good electrical and optical properties, etc. TiN is presently being used in cutting tools, solar-control films and other micro-electronic applications. For this reason, it was interesting to develop a new composite from scrap aluminium chips reinforced with TiN +Al2O3 ceramic powders and to examine its tailored beahviour of these composites. The thermal effects of laser cutting and effects of main operating parameters such as laser power, and cutting speed on the cutting edge and on the cutting surface were examined. The evolution of the microhardness underneath the cutting surface due to laser power is also examined. The composite used in this study was produced through combined method of powder metallurgical (P/M) and thixoforming (Semi solid). Microstructure of cutting edge and cutting surfaces are investigated in detail by scanning electron microscopy (SEM). Cutting surfaces have been analyzed with 3D optical surface roughness-meter (3D–SurfaScan). Roughness evaluations were taken as optimization criteria as a function of the cutting surface and cutting parameters (power, speed, gas pressure etc.) that have been carried out by Taguchi method. A simple and useful tool was proposed for using in real manufacturing environment