With the in-depth implementation of the magnesium alloy application development and industrialization "project, the enterprise in the actual production appeared many problems, such as technology and safety problems. This is because most of the domestic magnesium alloy die-casting business for the first time contact of magnesium alloy. Therefore, this paper will introduce the mechanical processing technology and safety operation regulations of magnesium alloy die casting parts.

1 mechanical processing of magnesium alloy

The density of magnesium alloy is lighter than aluminum alloy 36%, lighter than zinc alloy 73%, lighter than steel 77%, which is considered to be the lowest quality structural metal materials. Machining of small quantities of magnesium alloy parts in the manual operation of the small machine tools; mass and efficient processing of magnesium alloy parts with special large automation machining center or computer numerical control machine tool will be more economical. Compared with the metal material with poor mechanical properties, the good performance of the magnesium alloy with good cutting performance is outstanding. For magnesium alloy, it can be cut at high cutting speed and feed rate, so that the machine can be reduced. Therefore, in performing the same tasks. If the magnesium alloy as the raw materials, can reduce the number of units of processing equipment, saving construction investment, reduce the area, reduce labor costs and management fees.

The consumption 1.1 magnesium alloy cutting power because of its good thermal conductivity of magnesium alloy, cutting force is small, so in the process of cooling speed is very fast, and long tool life, less stick a knife, which can reduce tool cost, shorten the downtime required for exchange of tools. Because the magnesium alloy is easy to cut, its chip breaking performance is very good, and it can be achieved by the end of one time.

Effect of 1.2 magnesium alloy material on the processing performance

Effect of 1.2.1 on chip formation

The chip type formed during machining process, which is related to the material composition, the shape of the part, the state of the alloy and the feed rate. When the car of magnesium alloy by using a single point cutting tool, bore, planing, milling, the chips generated can be divided into 3 categories: A. in the large amount of feed to form coarse and off chip chip: B. in the medium feed rate formation of short length and off chip chip; C. under low feed shaped growth and curl chip.

Effect of 1.2.2 on the distortion of the twisted

Because of the high specific heat and heat conduction of magnesium, the heat generated by the friction will spread quickly to all parts of the parts, so it will not produce high temperature when the magnesium alloy is processed. However, in the case of high cutting speed and feed rate, the heat generated by the part is also very high, and it is likely that the temperature is too high and the distortion is too high.

Effect of 1.2.3 on thermal expansion

In the design of the thermal expansion coefficient of magnesium, it must be considered in the design of the thermal expansion coefficient of magnesium. If there is a considerable quantity of heat in the process, it is likely to affect the accuracy of the parts. The thermal expansion coefficient of magnesium is slightly higher than that of aluminum, which is obviously higher than that of steel, which is 26.6-27.4 m/m in the range of 20200.

1.3 effects of cutting tools on machining of magnesium alloy parts

Effect of 1.3.1 tool materials

The choice of cutting tool material for processing magnesium alloy depends on the amount of the machining required. Small batch processing, the general use of special long service life of ordinary steel knives; large batch processing, usually preferred inlaid with hard alloy tool; when processing large quantities and tolerance of very strict requirements can use reduction and compensation adjustment cost higher diamond cutter head to avoid the cumbersome.

1.3.2 tool design

Processed steel and aluminum cutting tools are usually also suitable for processing of magnesium alloy. However, due to the low cutting force and heat capacity of magnesium, the machining tool should have a large external angle, a larger gap, less number of blades and a smaller front angle. In addition, it is also very important to ensure the smooth surface of the cutting tool.

1.3.3 cutter blade grinding

An important principle of mechanical processing of magnesium alloy is shall keep the tool as high as possible sharp and smooth degree of, there must be no scratches, burr and bending. If the cutting tool of other metals, even if the cutting angle did not change, also should be re grinding and clear grinding.