Magnesium alloy with hot cracking resistance and low linear shrinkage

Abstract

The invention discloses a magnesium alloy with hot cracking resistance and low linear shrinkage, and belongs to the magnesium alloy field. The magnesium alloy is composed of elements of Mg, Zn, rare earths, Nb, Al and Li, and comprises, by weight, 0.2 to 9 percents of Zn, 0.0002 to 2 percents of Zr, 0.0002 to 16 percents of rare earths, 0.0002 to 4 percents of Nb, 0.001 to 1.49 percents of Al, 0.0002 to 9 percents of Li, and the balance Mg. According to the magnesium alloy, the structure of Beta phase is changed by adding rare earth elements and the Nb element into the magnesium alloy; grains are refined by adding the Li and Zr elements; and the crystallization latent heat is changed when the magnesium alloy is solidified by the combined action of the elements, so that the heat resistant magnesium alloy which has good mold-filling capacities, low shrinkage rate, good mechanical properties, machinability, mobility and die-casting properties and is suitable for casting is obtained.

Description

technical field [0001] The invention relates to a magnesium alloy, in particular to a hot-cracking-resistant high-performance cast magnesium alloy suitable for casting and forming. Background technique [0002] With the development of science and technology, vehicles represented by automobiles need to further develop new products with higher fuel efficiency by reducing the weight of the body. In the automobile manufacturing industry, magnesium alloy, as a new type of lightweight metal material, is used by automobile manufacturers to replace traditional cast iron in order to reduce the weight of the vehicle body. [0003] At present, the grades of domestic cast magnesium alloys include ZM2, ZM3, ZM4, ZM6, etc., among which, the above ZM series magnesium alloys contain cerium or lanthanum mixed rare earths, zinc and zirconium. The alloys of these grades have the characteristics of good mechanical properties and casting properties. [0004] In the process of realizing the pre...

AI Technical Summary

Problems solved by technology

[0004] In the process of realizing the present invention, the inventors found that there are at least the following problems in the prior art: when casting magnesium alloys, the molten metal is affected by volume shrinkage during the solidification process, and the internal stress is very large, which is easy to cause the casting surface Cracking, and even the phenomenon that the casting will break when the mold is opened

This hot cracking phenomenon seriously affects the application of cast magnesium alloys and affects the pass rate of magnesium alloy parts

The shrinkage rate of the above-mentioned die-casting magnesium alloy wire is 1.5-2%, and there is obvious thermal cracking phenomenon, which limits its application range