Casting method of magnesium alloy casting

Abstract

The invention provides a casting method of a magnesium alloy casting. With the method, advantages of different casting methods are utilized, and defects of the methods are overcome. With a special shell preparation method and a method for preventing magnesium alloy-casting mold interfacial reaction, a unique casting technology suitable for thin-wall complex magnesium alloy part production is formed. The method has important significance for developing magnesium alloy performance advantages and satisfying automotive magnesium alloy application requirements.

Description

technical field [0001] The invention belongs to the technical field of casting, and relates to a casting method of a magnesium alloy casting. technical background [0002] Magnesium alloy has the advantages of high specific strength and specific stiffness, good shock absorption, and easy recycling. It is considered to be the most promising structural lightweight material for mechanical products such as automobiles and transportation. The existing magnesium alloy forming processing technology is difficult to meet the application requirements of magnesium alloys, which affects the application of magnesium alloys. [0003] Magnesium alloys are formed by casting and plastic deformation. Due to the difficulty of plastic processing of magnesium alloys, casting is the main method for forming magnesium alloys. At present, the casting method used for magnesium alloy is also relatively single, mainly die casting, accounting for about 90%. Magnesium alloy die casting has the advantag...

AI Technical Summary

Problems solved by technology

At present, the casting method used for magnesium alloy is also relatively single, mainly die casting, accounting for about 90%

Magnesium alloy die casting has the advantages of high production efficiency, high casting dimensional accuracy, and low surface roughness, but the investment in molds and equipment is large, and it is difficult to produce parts with complex shapes and structures due to factors such as mold structure and technology.

In addition, ordinary die-casting parts are prone to form diffusely distributed micro-pores, which expand at high temperatures and cause casting deformation and surface bubbling. Therefore, ordinary die-casting magnesium alloy parts cannot be strengthened by heat treatment, nor can they be used at higher temperatures

Ordinary sand casting is not suitable for casting thin-walled castings due to its low dimensional accuracy and high roughness

The investment casting method is suitable for casting castings with high dimensional accuracy and complex shapes. However, investment casting generally adopts hot shell and gravity pouring. The interface reaction between magnesium alloy and hot shell is large, and the process of preventing interface reaction is complicated. Melting of wax mold is used. The mold casting method is also not suitable for mass production of castings with large structural dimensions.

Lost foam casting is a casting method suitable for the production of thin-walled complex castings. In recent years, magnesium alloy lost foam casting technology has been studied at home and abroad. Because the foam pattern of lost foam casting decomposes and absorbs heat in the liquid metal filling mold, and Magnesium alloys have small heat capacity, low solidification latent heat, and large solidification range. In order to meet the needs of mold filling, the pouring temperature must be greatly increased, which leads to oxidation of magnesium liquid, increased gas absorption, and low performance of castings.

[0004] To sum up, the existing casting methods of magnesium alloys cannot meet the application requirements of magnesium alloys well, and new casting methods need to be found