Effective method for improving plastic molding capacity of high-strength Mg-Gd-Y-Nd-Zr magnesium alloy

Abstract

The invention relates to the field of plasticity improvement of high-strength magnesium alloys, in particular to a method for improving plastic molding cavity of a high-strength Mg-Gd-Y-Nd-Zr magnesium alloy by effectively using an element Li, and solves the problem of weaker high-strength plasticity. Under the precondition of keeping relative contents of all elements in the alloy invariable, 5-20weight% of Li element is added to form a beta-Li phase with higher plasticity deformation capacity in the alloy; the volume fraction (20-90%) of forming the beta-Li phase is controlled to prepare a lithium-contained Mg-Gd-Y-Nd-Zr alloy with high strength and better plasticity; the alloy is smelted and hot rolled subsequently to prepare a plate; and the machining process is simple and convenient to operate. The tensile strength of the material under cast-state condition is ob=120-250 MPa, the yield strength is o0.2=80-150 MPa, the ductility is delta=10-30%, and the density is 1.50-1.89 g / cm3;and the plate cannot generate the edge cracking phenomenon after deformation with 40% of rolling quantity at room temperature.

Description

technical field

[0001] The invention relates to the field of improving the plasticity of high-strength magnesium alloys, in particular to a method for effectively utilizing element Li to improve the plastic forming ability of high-strength Mg-Gd-Y-Nd-Zr magnesium alloys. Background technique

[0002] Among all metal structural materials, the density of magnesium alloy is the lowest, which is 2 / 3 of that of aluminum alloy and 1 / 4 of that of stainless steel. If magnesium alloy materials can mostly replace stainless steel and aluminum alloys in aircraft and vehicles, it will not only achieve the purpose of reducing weight and speed, but also effectively solve a series of problems related to energy saving and environmental protection. At the same time, magnesium alloys also have the advantages of high specific strength and specific stiffness, strong resistance to high-energy particle penetration, good electromagnetic shielding performance, good damping performance, and excellent...

Examples

Embodiment 1

[0043] In this embodiment, an effective method for improving the plastic forming ability of the high-strength Mg-Gd-Y-Nd-Zr magnesium alloy is as follows:

[0044]Ⅰ), the lithium-containing Mg-7%Gd-5%Y-1%Nd-0.5%Zr-10%Li alloy composition used

[0045] Use lithium-containing high-strength Mg-7%Gd-5%Y-1%Nd-0.5%Zr-10%Li alloy, its chemical composition (percentage by weight) is: gadolinium content is 7%; yttrium content is 5% %; neodymium content 1%; zirconium content 0.5%; lithium content 10%; magnesium balance.

[0046] Ⅱ), alloy smelting

[0047] The Mg-Gd-Y-Nd-Zr alloy and pure lithium ingots are melted in a vacuum smelting furnace, and the alloy is smelted under the protection of argon, and the temperature is kept at 770°C for 4 hours, and then cast in the furnace .

[0048] Ⅲ), homogenization treatment

[0049] The high-strength Mg-7%Gd-5%Y-1%Nd-0.5%Zr-10%Li alloy is kept at 400°C for 8 hours and tightly wrapped with aluminum foil to prevent the alloy from burning due to...

Embodiment 2

[0059] In this embodiment, an effective method for improving the plastic forming ability of the high-strength Mg-Gd-Y-Nd-Zr magnesium alloy is as follows:

[0060] Ⅰ), the lithium-containing Mg-9%Gd-6%Y-1.5%Nd-0.5%Zr-10%Li alloy composition used

[0061] Use lithium-containing high-strength Mg-9%Gd-6%Y-1.5%Nd-0.5%Zr-10%Li alloy, its chemical composition (weight percentage) is: gadolinium content is 9%; yttrium content is 6% %; neodymium content 1.5%; zirconium content 0.5%; lithium content 10%; magnesium balance.

[0062] Ⅱ), alloy smelting

[0063] Same as Example 1.

[0064] Ⅲ), homogenization treatment

[0065] Same as Example 1.

[0066] Ⅳ), plastic deformation

[0067] Same as Example 1.

[0068] Ⅴ) Microstructure characterization

[0069] The tissue observation method is the same as in Example 1. XRD results show that the sample of Example 2 mainly contains β-Li, α-Mg and Mg5Gd phases. Optical observation results show that the volume fraction of the quasi-crysta...

technical field

[0001] The invention relates to the field of improving the plasticity of high-strength magnesium alloys, in particular to a method for effectively utilizing element Li to improve the plastic forming ability of high-strength Mg-Gd-Y-Nd-Zr magnesium alloys. Background technique

[0002] Among all metal structural materials, the density of magnesium alloy is the lowest, which is 2 / 3 of that of aluminum alloy and 1 / 4 of that of stainless steel. If magnesium alloy materials can mostly replace stainless steel and aluminum alloys in aircraft and vehicles, it will not only achieve the purpose of reducing weight and speed, but also effectively solve a series of problems related to energy saving and environmental protection. At the same time, magnesium alloys also have the advantages of high specific strength and specific stiffness, strong resistance to high-energy particle penetration, good electromagnetic shielding performance, good damping performance, and excellent...

Examples

Embodiment 1

[0043] In this embodiment, an effective method for improving the plastic forming ability of the high-strength Mg-Gd-Y-Nd-Zr magnesium alloy is as follows:

[0044]Ⅰ), the lithium-containing Mg-7%Gd-5%Y-1%Nd-0.5%Zr-10%Li alloy composition used

[0045] Use lithium-containing high-strength Mg-7%Gd-5%Y-1%Nd-0.5%Zr-10%Li alloy, its chemical composition (percentage by weight) is: gadolinium content is 7%; yttrium content is 5% %; neodymium content 1%; zirconium content 0.5%; lithium content 10%; magnesium balance.

[0046] Ⅱ), alloy smelting

[0047] The Mg-Gd-Y-Nd-Zr alloy and pure lithium ingots are melted in a vacuum smelting furnace, and the alloy is smelted under the protection of argon, and the temperature is kept at 770°C for 4 hours, and then cast in the furnace .

[0048] Ⅲ), homogenization treatment

[0049] The high-strength Mg-7%Gd-5%Y-1%Nd-0.5%Zr-10%Li alloy is kept at 400°C for 8 hours and tightly wrapped with aluminum foil to prevent the alloy from burning due to...

Embodiment 2

[0059] In this embodiment, an effective method for improving the plastic forming ability of the high-strength Mg-Gd-Y-Nd-Zr magnesium alloy is as follows:

[0060] Ⅰ), the lithium-containing Mg-9%Gd-6%Y-1.5%Nd-0.5%Zr-10%Li alloy composition used

[0061] Use lithium-containing high-strength Mg-9%Gd-6%Y-1.5%Nd-0.5%Zr-10%Li alloy, its chemical composition (weight percentage) is: gadolinium content is 9%; yttrium content is 6% %; neodymium content 1.5%; zirconium content 0.5%; lithium content 10%; magnesium balance.

[0062] Ⅱ), alloy smelting

[0063] Same as Example 1.

[0064] Ⅲ), homogenization treatment

[0065] Same as Example 1.

[0066] Ⅳ), plastic deformation

[0067] Same as Example 1.

[0068] Ⅴ) Microstructure characterization

[0069] The tissue observation method is the same as in Example 1. XRD results show that the sample of Example 2 mainly contains β-Li, α-Mg and Mg5Gd phases. Optical observation results show that the volume fraction of the quasi-crysta...

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