High-toughness magnesium alloy and preparation method thereof

Abstract

The invention discloses a high-toughness magnesium alloy. The alloy is characterized by comprising the following components in percentage by mass: 1.7 to 2.5 weight percent of Sm, 0.4 to 0.8 weight percent of Mn, 0.2 to 0.6 weight percent of Ca, 0.2 to 0.6 weight percent of Zn and the balance of Mg and inevitable impurities. By controlling the adding amount of Sm, Mg, Zn, Ca and Mn, on one hand, rare earth Sm, Mg, Zn and Ca form a large number of MgZnCaSm and MgZnSm nanophases, a large number of alpha-Mn nanophases exist in an alloy structure, the nanophases play a role in strengthening a magnesium matrix, the strength of the alloy is improved, the nanophases are small in size and can be dispersed and distributed on the magnesium alloy matrix, the influence on the ductility of the matrix is not large, the tensile strength of the magnesium alloy can be 400 MPa-450 MPa, the yield strength of the magnesium alloy can be 390 MPa-420 MPa, and the ductility of the magnesium alloy can be 15% or above.

Description

technical field [0001] The invention belongs to the technical field of magnesium alloys, and in particular relates to a high-strength and toughness magnesium alloy and a preparation method thereof. Background technique [0002] As the lightest metal structural material, magnesium alloy has a series of advantages such as low density, high specific strength, good thermal conductivity and excellent damping and shock absorption performance. It has broad application prospects in the fields of aerospace, transportation and mobile communication. However, the strength of traditional magnesium alloys is not high, which still faces some challenges in practical applications. At present, researchers mainly control the microstructure of magnesium alloys through alloying, plastic deformation and heat treatment, in order to obtain new magnesium alloys with excellent comprehensive mechanical properties, and then meet the needs of practical applications. [0003] Existing studies have shown...

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Problems solved by technology

[0004] The patent (CN105088038A) proposes a high thermal conductivity and corrosion-resistant Mg-1.5~6%Sm-0.001~1.2%Ca-0.5~3.0%Zn-0.3~2.5%Mn alloy, and its extrusion deformation process is: the ingot is cast in 350-420°C for 2-24h homogenization treatment, extrusion speed 0.1-6mm / s, extrusion ratio 14-30, water quenching after extrusion, but no heat treatment process after extrusion deformation and mechanics after extrusion deformation The performance is explained; Guan Kai et al obtained fine dynamic recrystallization grains (~0.47m) by extrusion of Mg-3.5Sm-0.6Zn-0.5Zr alloy, and after further T5 aging treatment, the yield of the alloy The strength reached ~416MPa, and the elongation was ~5.1%. The patent (CN111485453.A) proposed a deformed magnesium alloy containing neodymium, samarium, light rare earth elements and high Mn content and its preparation method. The mass composition ratio is: calcium: 0.3-1.9%; aluminum: 0.3-1.5%; zinc: 0.2-1.7%; manganese: 0.3-2.8%; light rare earth (neodymium or samarium): 0.3-3.0%, the material can The tensile strength reaches 368-435MPa, and the elongation is 4-13%, but the disadvantage of this alloy is that the elongation of the patented alloy is less than 10% when the tensile strength reaches above 390MPa, showing obvious Mismatch of strength and plasticity

[0005] At present, high strength and low elongation at break are common problems in high-strength wrought magnesium alloy materials, which greatly limits its application. Therefore, the development of high strength and high elongation at break is of great significance to promote the application of magnesium alloy materials.

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