Magnesium is inseparable part of modern metallurgy. Early investigations related to the constituents of railroad iron and steel, of heat stress and heat treatment and related problems in the manufacturing process. Other says that the chemistry of metals and metal alloys, properties of metals at high temperatures, the working of metal in the foundry process, and testing of metals for compliance with Government specifications. World War I and World War II show that fact. Then many chemical, mechanical and structural properties of aluminum and magnesium (also platinum, rhodium, irridium, and palladium) were investigated with military meaning. In the same time scientist try to understand the metals corrosion processes, the properties of magnesium alloys, the metallurgy of nickel and its alloys, the testing of tool steels, and the mechanical properties of cast iron.
Magnesium has been used in manufacturing notebook computer frames, video cameras, digital cameras, PDAs and other consumer electronics products because of its high strength to weight ratio. When magnesium is alloyed with aluminum, the resultant material is very light and strong, and easily machinable. The main concern in machining magnesium alloy is the danger of fire ignition when dry cutting. Fire may occur when the melting point of the alloy (400-600 o C) is exceeded during machining. We have to follow some general points about machining magnesium.
Firstly, the slower the machining speed and the larger the chips, the lower the workpiece temperature will be. Due to this reason, some companies have modified woodworking tools for machining magnesium so as to achieve larger chips and lower fire hazard. The cutting tools used should have relief and clearance angles that are sufficiently large to prevent unnecessary cutting tool-workpiece friction, thus lowering the heat generated during the cutting process.
Second, cleaning the machining centers regularly and storing the magnesium chips correctly are important aspects of machining magnesium. Keep a container of cast iron chips near by when machining magnesium. Thirdly, if coolants are necessary for high speed machining, do not use water-based lubricants. Instead use a light mineral oil, or a water-soluble cutting fluid such as Castrol Hysol MG specially formulated for machining magnesium. Some companies in Japan use semi-dry machining via a misting system. The forth important point is to monitor the workpiece temperature during machining.
We can summary that magnesium and magnesium alloys are increasingly used for making electronic and machining products, tools and many others. Its metallurgical purposes develop every day.