High-toughness heat-resisting pressure casting Mg-Y-Er alloy and preparation method thereof

Abstract

The invention provides a high-toughness heat-resisting pressure casting Mg-Y-Er alloy and a preparation method thereof. The high-toughness heat-resisting pressure casting Mg-Y-Er alloy comprises elements including, by mass percent, 3.0%-7.0% of RE, 1.2%-4.2% of Zn, 0.5%-1.2% of Al, 0.1%-0.3% of Mn, 0.01%-0.08% of M and the balance Mg, wherein M is one or two elements of Ti and B. The preparation method comprises the steps that firstly, materials are prepared according to Mg-Y-Er alloy components; secondly, industrial pure magnesium ingots are melted; thirdly, the temperature is raised to 720 DEG C, industrial pure zinc, Mg-Y, Mg-Er and Mg-Mn intermediate alloys are added and stirred to be completely melted; fourthly, the temperature is raised to 730 DEG C, after industrial pure aluminum ingots, Al-Ti, Al-Ti-B and Al-B intermediate alloys are sequentially added, magnesium alloy melt is obtained after refining; and fifthly, the magnesium alloy melt is cooled to a pressure casting temperature so as to be subjected to pressure casting, and a pressure casting alloy is obtained. After the alloy is subjected to pressure casting, the strength of extension of the alloy in a pressure castingstate at the room temperature reaches 312 MPa, the strength of extension of the alloy at the high temperature of 200 DEG C reaches 205 MPa, the room temperature ductility reaches 13.0%, the high-toughness heat-resisting pressure casting Mg-Y-Er alloy can be used without aging or solution heat treatment, and the high-end requirement of aerospace and other industries for light weight is met.

Description

technical field [0001] The invention relates to a high-strength, toughness and heat-resistant die-casting Mg-Y-Er alloy, which meets the high-end requirements of aerospace, automobile, telecommunications and other industries for lightweight development. The invention also relates to a preparation method of a high-strength and tough heat-resistant die-casting Mg-Y-Er alloy, which belongs to the field of industrial magnesium alloys and their manufacture. Background technique [0002] As the lightest engineering metal material (the density of magnesium is 2 / 3 of aluminum and 1 / 4 of steel), its specific strength is obviously higher than that of aluminum alloy and steel. Higher than engineering plastics, it also has a series of advantages such as good castability, good machinability, good thermal conductivity, damping, strong electromagnetic shielding ability and easy recycling. Wide application prospects. Magnesium alloy has become an ideal material to replace aluminum alloy, ...

AI Technical Summary

Problems solved by technology

[0010] In order to solve the industrial problem that the existing die-casting magnesium alloy cannot reach the performance of die-casting aluminum alloys such as A380 due to insufficient strength, toughness and heat resistance, resulting in its application being greatly restricted, the present invention provides high-strength, toughness and heat-resistant die-casting Mg-Y- Er alloy and its preparation method for pressure casting. After the alloy is pressure cast, the room temperature tensile strength of the die-cast alloy reaches 312MPa, the high temperature tensile strength at 200°C reaches 205MPa, and the room temperature elongation reaches 13.0%.

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