High-toughness casting magnesium alloy thermal treatment method

Abstract

The invention provides a high-toughness casting magnesium alloy thermal treatment method. The method comprises the steps that mixed gas of argon and hydrogen is adopted as a hydrogen element to replace strengthened atmosphere, the pressure is set to be 0.14-0.155 MPa, and the solution treatment temperature is set to be 500-510 DEG C; heat preservation and exhaust are performed, nitrogen is introduced and then quenching is performed, wherein machine oil under the temperature of 102-108 DEG C is adopted as a quenching medium. In order to meet the active requirements of various industries for high-strength thin-wall magnesium alloy castings, on the basis of magnesium-rare earth-zirconium-zinc(silver) high-strength casting magnesium alloy organization characteristics, the requirement for the rapid and efficient thermal treatment technology and the requirement for safety production, the invention creatively provides a method for performing efficient and stable thermal treatment with the high safety coefficient on magnesium-rare earth-zirconium-zinc(silver) high-strength casting magnesium alloy.

Description

technical field [0001] The invention relates to the technical field of metal materials, in particular to a heat treatment method for a high-strength and toughness cast magnesium alloy. Background technique [0002] Due to the increasingly urgent requirements for weight reduction, energy saving, environmental protection, and high integration and thinning of components in aviation, aerospace, military and automotive industries, cast magnesium alloys have been widely used in these fields in recent years. Due to the characteristics of low density, abundant resources, convenient recycling, high specific strength and high specific stiffness, magnesium alloy has gradually established its position as the third largest metal engineering material in the world. Although cast magnesium alloys have superior performance and broad application prospects, the active chemical properties of magnesium elements lead to complex heat treatment processes for cast magnesium alloy materials, especial...

AI Technical Summary

Problems solved by technology

However, this process method is not suitable for magnesium-zinc-rare earth-zirconium-silver high-strength thin-walled magnesium alloy castings. First, the magnesium-zinc-rare earth-zirconium-silver high-strength cast magnesium alloy contains Magnesium-rare earth-silver ternary phase with better high temperature stability of the ternary compound, the ternary phase needs to be at 500°C to have a better hydrogen replacement strengthening effect; secondly, for thin-walled magnesium alloy castings, under long-term heat preservation conditions, It will lead to grain growth and damage the mechanical properties of castings; again, heating a single hydrogen atmosphere with a high risk factor to 500°C and maintaining a positive pressure state for a long time will easily lead to safety accidents, making the hydrogen atmosphere heat treatment furnace a major source of danger