Beryllium containing single phase alpha magnesium-lithium alloy and processing technology thereof

Abstract

The invention discloses a beryllium containing single phase alpha magnesium-lithium alloy and a processing technology thereof. The alloy is composed of the following components in percentage by weight: 2.0 to 4.0 wt.% of Li, 0.1 to 0.4 wt.% of Be, 0.2 to 0.4 wt.% of Co, 1.0 to 3.0 wt.% of Cu, 0.2 to 0.4 wt.% of Ge, 0.1 to 0.2 wt.% of Hf, 0.2 to 0.4 wt.% of Sb, 0.6 to 0.8 wt.% of Al, and the balance being magnesium. The formula of the alloy is optimized, the melting technology and heat treatment parameters are also optimized, the high temperature phase and strengthening phase of the magnesium-lithium alloy are perfectly matched, and finally the multi-component magnesium-lithium alloy with a strong heatproof performance is obtained. At a room temperature, the magnesium-lithium alloy has thefollowing indexes: yield strength: 120-140 MPa, tensile strength: 170-190 MPa, and elongation rate: 6-14%. At a temperature of 100 DEG C, the magnesium-lithium alloy has the following indexes: yield strength: 110-130 MPa, tensile strength: 150-160 MPa, and elongation rate: 18-20% The alloy melting method is simple, the production cost is low, and the alloy is suitable for industrial large scale application.

Description

technical field [0001] The invention relates to the technical field of alloys, in particular to a magnesium-lithium alloy. Background technique [0002] The density of lithium is only 0.53g / cm 3 , adding it to magnesium to form a magnesium-lithium alloy. The density of magnesium-lithium alloy is about 1.3-1.6g / cm 3 , is the structural alloy with the lowest density and the highest specific strength today. According to different lithium content and structure, magnesium-lithium alloys can be divided into three categories: alloys containing less than 5.5wt.% lithium, whose structure is a solid solution (α phase) of lithium dissolved in hcp magnesium; lithium containing more than 10.2wt. .% of the alloy, its organization is a uniform bcc solid solution (β phase). When the lithium content is between 5.5wt.% and l0.2wt.%, the alloy is a duplex a+β structure. [0003] Magnesium-lithium alloy is light, high in specific stiffness, conductive and thermally conductive, and can be u...

AI Technical Summary

Problems solved by technology

However, these strengthening effects decrease rapidly with the increase of temperature, and the obtained alloy materials have relatively poor mechanical properties at room temperature

Magnesium-lithium-zinc alloys belong to the precipitation hardening type, and the cost is relatively low, but the mechanical properties of this type of alloy are relatively poor at room temperature

Moreover, existing magnesium-lithium alloys generally have problems such as low high-temperature strength, poor casting performance, and long slag treatment process.

In addition, in recent years, the high-temperature-resistant and high-strength magnesium-lithium alloy formulations that have appeared internationally all contain precious elements, which are not suitable for large-scale industrial production and application.

The α-phase is a close-packed hexagonal crystal, which has poor plastic deformation ability, difficult deformation processing, low processing efficiency, and difficult to further secondary molding, resulting in a very low share of deformed α-phase magnesium-lithium alloys on the market, which seriously restricts its ( Large-scale application of sheets, profiles, pipes, etc.) in aerospace and electronics industries