Machining of light metals

Magnesium, aluminium and titanium are the only light metals that are also u sed in construction. They offer a significant prerequisite for weight reduc tion of workpieces. Especially the automotive and the aerospace industry ha ve an increasing interest in using these lightweight materials as well as t heir alloys. The machining of light metals however is accompanied with several problems. With increasing the cutting speed high adhesive and abrasive effects betwe en the cutting tool material and the workpiece material can occur. These ef fects lead to unsteady processes and also have a negative influence on the quality of functional surfaces as well as their subsurface properties. The influence of cutting tool materials, tool coatings and cutting conditio ns affecting the process when cutting magnesium, aluminium and titanium all oys is described. Adhesion can be reduced when machining magnesium and alum inium alloys in particular by the application of diamond-coated tools and b y PCD-inserts. Diamond tools, due to their low coefficient of friction and the high thermal conductivity, furthermore contribute to the decrease of th e thermal load within the contact zone between workpiece and cutting tool. Subsequently the danger of magnesium chip ignition can be minimized. For th e machining of titanium alloys modern coatings based on (Ti,Al)N and TiCTiN are applied to reduce the adhesive and abrasive wear.