A kind of high-strength casting magnesium alloy and preparation method thereof

Abstract

The invention is a high-strength casting magnesium alloy, which is a Mg-Bi-Al-Zn-Sr alloy, and the weight percentages of its components are: Bi3-8.0wt%; Al 0.5-4.0wt%; Zn 0.1-1.0wt%; Sr 0.05-0.15wt%, the rest is Mg. In the present invention, Bi element is used as the main alloy element, and a large amount of Mg3Bi2 phase is formed through a simple alloying method, supplemented by a small amount of aluminum element and zinc element to improve the strength of the alloy, thereby developing a high-strength cast magnesium alloy in this alloy series , the tensile strength of the alloy is 276-296MPa, the yield strength is 155-170MPa, and the elongation is 5.3-7.3%, achieving mechanical properties comparable to those of rare earth magnesium alloys.

Description

technical field

[0001] The invention relates to a non-rare earth low-cost high-strength cast magnesium alloy and a preparation method thereof, in particular to a Mg-Bi-Al-Zn-Sr alloy and a preparation method thereof, belonging to the field of metal materials and metallurgy. Background technique

[0002] Magnesium alloy is currently the lightest metal engineering structure material in practical application, and the density of pure magnesium is about 1.74g / cm 3 , its density is about 1 / 4 of steel, 1 / 3 of zinc, and 2 / 3 of aluminum alloy. Magnesium alloys have the characteristics of high specific strength, excellent mechanical cutting performance and damping and shock absorption performance, which meet the urgent needs of the modern automobile industry for weight reduction and environmental protection. Since the 1980s, with the rapid development of the automobile industry, a large number of magnesium alloy materials have been used in automobile parts, among which the commercial...

Examples

Embodiment 1

[0035] (1) Take raw material by the mass percent of alloy Mg-3.8Bi-3.2Al-0.5Zn-0.05Sr (wt%): pure Bi, pure Al, pure Zn and Mg-5Sr master alloy, all the other are Mg (per 1000 The gram target alloy can be prepared by 10 grams of Mg-5Sr, 32 grams of Al, 5 grams of Zn, 38 grams of Bi and 917 grams of Mg); and do a good job of surface treatment of raw materials (such as removing dirt, scale, etc.).

[0036] (2) First clean the melting furnace and heat it to 450°C, put the magnesium ingot preheated to 200°C into the crucible of the melting furnace, set the furnace temperature to 720°C, and slowly heat the heating rate to 20-40°C / min And maintain the set furnace temperature.

[0037] (3) After the pure magnesium ingots are completely melted, respectively add pure Bi, pure Al, pure Zn and Mg-5Sr intermediate alloys preheated to about 200°C to the magnesium melt, raise the furnace temperature to 730°C, and keep warm 5 to 10 minutes, then mechanically stirred for 3 to 5 minutes, then ...

Embodiment 2

[0042] (1) Take raw material by the mass percent of alloy Mg-6Bi-2.0Al-0.6Zn-0.08Sr (wt%): pure Bi, pure Al, pure Zn and Mg-5Sr master alloy, all the other are Mg; And do well Surface treatment of raw materials (such as removal of dirt, scale, etc.).

[0043] (2) First clean the melting furnace and heat it to 450°C, put the magnesium ingot preheated to 200°C into the crucible of the melting furnace, set the furnace temperature to 720°C, and slowly heat the heating rate to 20-40°C / min And maintain the set furnace temperature.

[0044] (3) After the pure magnesium ingots are completely melted, respectively add pure Bi, pure Al, pure Zn and Mg-5Sr intermediate alloys preheated to about 200°C to the magnesium melt, raise the furnace temperature to 730°C, and keep warm 5 to 10 minutes, then mechanically stirred for 3 to 5 minutes, then filled with argon for refining and degassing, then adjusted the furnace temperature to the pouring temperature of 720°C, stood for 2 to 10 minutes,...

Embodiment 3

[0049] (1) Take raw material by the mass percent of alloy Mg-7.0Bi-1.0Al-1.0Zn-0.08Sr (wt%): pure Bi, pure Al, pure Zn and Mg-5Sr master alloy, all the other are Mg; And do Good raw material surface treatment (such as removal of dirt, scale, etc.).

[0050] (2) First clean the melting furnace and heat it to 450°C, put the magnesium ingot preheated to 200°C into the crucible of the melting furnace, set the furnace temperature to 720°C, and slowly heat the heating rate to 20-40°C / min And maintain the set furnace temperature.

[0051] (3) After the pure magnesium ingots are completely melted, respectively add pure Bi, pure Al, pure Zn and Mg-5Sr intermediate alloys preheated to about 200°C to the magnesium melt, raise the furnace temperature to 730°C, and keep warm 5 to 10 minutes, then mechanically stirred for 3 to 5 minutes, then filled with argon for refining and degassing, then adjusted the furnace temperature to the pouring temperature of 720°C, stood for 2 to 10 minutes, a...

technical field

[0001] The invention relates to a non-rare earth low-cost high-strength cast magnesium alloy and a preparation method thereof, in particular to a Mg-Bi-Al-Zn-Sr alloy and a preparation method thereof, belonging to the field of metal materials and metallurgy. Background technique

[0002] Magnesium alloy is currently the lightest metal engineering structure material in practical application, and the density of pure magnesium is about 1.74g / cm 3 , its density is about 1 / 4 of steel, 1 / 3 of zinc, and 2 / 3 of aluminum alloy. Magnesium alloys have the characteristics of high specific strength, excellent mechanical cutting performance and damping and shock absorption performance, which meet the urgent needs of the modern automobile industry for weight reduction and environmental protection. Since the 1980s, with the rapid development of the automobile industry, a large number of magnesium alloy materials have been used in automobile parts, among which the commercial...

Examples

Embodiment 1

[0035] (1) Take raw material by the mass percent of alloy Mg-3.8Bi-3.2Al-0.5Zn-0.05Sr (wt%): pure Bi, pure Al, pure Zn and Mg-5Sr master alloy, all the other are Mg (per 1000 The gram target alloy can be prepared by 10 grams of Mg-5Sr, 32 grams of Al, 5 grams of Zn, 38 grams of Bi and 917 grams of Mg); and do a good job of surface treatment of raw materials (such as removing dirt, scale, etc.).

[0036] (2) First clean the melting furnace and heat it to 450°C, put the magnesium ingot preheated to 200°C into the crucible of the melting furnace, set the furnace temperature to 720°C, and slowly heat the heating rate to 20-40°C / min And maintain the set furnace temperature.

[0037] (3) After the pure magnesium ingots are completely melted, respectively add pure Bi, pure Al, pure Zn and Mg-5Sr intermediate alloys preheated to about 200°C to the magnesium melt, raise the furnace temperature to 730°C, and keep warm 5 to 10 minutes, then mechanically stirred for 3 to 5 minutes, then ...

Embodiment 2

[0042] (1) Take raw material by the mass percent of alloy Mg-6Bi-2.0Al-0.6Zn-0.08Sr (wt%): pure Bi, pure Al, pure Zn and Mg-5Sr master alloy, all the other are Mg; And do well Surface treatment of raw materials (such as removal of dirt, scale, etc.).

[0043] (2) First clean the melting furnace and heat it to 450°C, put the magnesium ingot preheated to 200°C into the crucible of the melting furnace, set the furnace temperature to 720°C, and slowly heat the heating rate to 20-40°C / min And maintain the set furnace temperature.

[0044] (3) After the pure magnesium ingots are completely melted, respectively add pure Bi, pure Al, pure Zn and Mg-5Sr intermediate alloys preheated to about 200°C to the magnesium melt, raise the furnace temperature to 730°C, and keep warm 5 to 10 minutes, then mechanically stirred for 3 to 5 minutes, then filled with argon for refining and degassing, then adjusted the furnace temperature to the pouring temperature of 720°C, stood for 2 to 10 minutes,...

Embodiment 3

[0049] (1) Take raw material by the mass percent of alloy Mg-7.0Bi-1.0Al-1.0Zn-0.08Sr (wt%): pure Bi, pure Al, pure Zn and Mg-5Sr master alloy, all the other are Mg; And do Good raw material surface treatment (such as removal of dirt, scale, etc.).

[0050] (2) First clean the melting furnace and heat it to 450°C, put the magnesium ingot preheated to 200°C into the crucible of the melting furnace, set the furnace temperature to 720°C, and slowly heat the heating rate to 20-40°C / min And maintain the set furnace temperature.

[0051] (3) After the pure magnesium ingots are completely melted, respectively add pure Bi, pure Al, pure Zn and Mg-5Sr intermediate alloys preheated to about 200°C to the magnesium melt, raise the furnace temperature to 730°C, and keep warm 5 to 10 minutes, then mechanically stirred for 3 to 5 minutes, then filled with argon for refining and degassing, then adjusted the furnace temperature to the pouring temperature of 720°C, stood for 2 to 10 minutes, a...

Images