CN104674092B

CN104674092B - A kind of Mg Al Zn system heat resistance magnesium alloy containing Sm and preparation method thereof

Info

Publication number: CN104674092B
Application number: CN201510088986.7A
Authority: CN
Inventors: 陈君; 张清; 李全安; 李梅菊; 朱宏喜; 周耀; 严景龙
Original assignee: Henan University of Science and Technology
Current assignee: Henan University of Science and Technology
Priority date: 2015-02-27
Filing date: 2015-02-27
Publication date: 2017-03-01
Anticipated expiration: 2035-02-27
Also published as: CN104674092A

Abstract

The present invention a kind of Mg Al Zn system heat resistance magnesium alloy containing Sm of offer and preparation method thereof, each component and its percetage by weight are：Al be 2～11%, Zn be 1.5～3%, Sm be 1.8～4%, Ag be 0.2～1.8%, Ca be 0.1～1.9%, Sr be 0.1～0.7%, Sn be 0.1～0.9%, Ti be 0.1～0.5%, balance of Mg；The present invention passes through to introduce appropriate rare earth element Sm, alkaline earth element Ca and Sr and other elements Ag, Sn, Ti, by the method for multicomponent microalloying, alloy is modified, and the cast alloy obtaining is carried out heat treatment, Mg Al Zn system alloy prepared by the present invention has higher room temperature and Testing Tensile Strength at Elevated Temperature, plasticity has also obtained larger improvement, and microscopic structure is uniform；The magnesium alloy cost that the present invention provides is relatively low, and melting and Technology for Heating Processing are simple.

Description

A kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm and preparation method thereof

Technical field

The invention belongs to metal material and metallurgical technology field, specifically a kind of Mg-Al-Zn system heat resistant magnesium containing Sm Alloy and preparation method thereof.

Background technology

Magnesium and magnesium alloy as the lightest structural metallic materials in engineer applied, have low density, high specific strength and Specific stiffness, excellent damping characteristics and good thermal diffusivity, the application in many fields has very significant advantage, special It is not, in terms of Aeronautics and Astronautics and automobile, motorcycle, high speed light rail train, there is the advantage being difficult to substitute.Commercial magnesium closes at present Gold substantially can be divided into cast magnesium alloy and wrought magnesium alloy two big class.In cast magnesium alloy, AZ system is cheap due to having Price and good casting technique and be most widely used, mainly have AZ91 series and AM60/50 series, but two kinds of alloys Heat resistance is all poor, and after ambient temperature is more than 120 DEG C, the intensity of magnesium alloy can suddenly decline, and limits it in many works Application on industry equipment and product.In order to expand range of application and the field of magnesium alloy, research work is entered to existing magnesium alloy A large amount of exploratory developments are gone, improving the room temperature of magnesium alloy and mechanical behavior under high temperature using alloying is important means, used Alloy element mainly has the other elements such as rare earth element and alkaline earth element and aluminum, zinc, stannum, in succession develops a series of heat-resisting Magnesium alloy, but all noble elements containing higher proportion in the composition of these alloys, cause cost of alloy higher, therefore continue The more excellent magnesium alloy of research and development heat-resisting quantity.

Content of the invention

It is an object of the invention to provide a kind of there is higher room temperature and Testing Tensile Strength at Elevated Temperature, microscopic structure uniformly and becomes This relatively low Mg-Al-Zn system heat resistance magnesium alloy containing Sm and preparation method thereof.

For solving above-mentioned technical problem, the technical solution used in the present invention is：

A kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm, each component and its percetage by weight are：Al is 2～11%, Zn For 1.5～3%, Sm be 1.8～4%, Ag be 0.2～1.8%, Ca be 0.1～1.9%, Sr be 0.1～0.7%, Sn be 0.1～ 0.9%, Ti are 0.1～0.5%, balance of Mg；

A kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm, each component and its percetage by weight are：Al for 4.79%, Zn is 2.97%, Sm be 2.84%, Ag be 0.92%, Ca be 0.28%, Sr be 0.32%, Sn be 0.25%, Ti be 0.19%, balance of Mg；

A kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm, each component and its percetage by weight are：Al for 6.12%, Zn is 2.55%, Sm be 3.61%, Ag be 0.92%, Ca be 0.84%, Sr be 0.56%, Sn be 0.39%, Ti be 0.22%, balance of Mg；

A kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm, each component and its percetage by weight are：Al for 10.39%, Zn is 1.87%, Sm be 2.84%, Ag be 0.77%, Ca be 1.14%, Sr be 0.61%, Sn be 0.14%, Ti be 0.14%, balance of Mg.

A kind of preparation method of heat resistance magnesium alloy as above, comprises the following steps：

1）According to above-mentioned percetage by weight weigh pure magnesium ingot, fine aluminium ingot, pure zinc granule, pure tin grain, fine silver ingot, in the middle of Mg-Sm Alloy, Mg-Sr intermediate alloy, Mg-Ca intermediate alloy and Al-Ti intermediate alloy, standby；

2）By step 1）The pure magnesium ingot that weighs, fine aluminium ingot, pure zinc granule, pure tin grain, fine silver ingot, Mg-Sm intermediate alloy, Mg- Sr intermediate alloy, Mg-Ca intermediate alloy and Al-Ti intermediate alloy drying and preheating 2h under the conditions of 180 ~ 200 DEG C, standby；

3）By step 2）Pure magnesium ingot after preheating, fine aluminium ingot, pure zinc granule, pure tin grain and fine silver ingot are in CO₂+SF₆Mixed gas Protection is lower to melt, be heated to when 700 ~ 720 DEG C adding Mg-Sm intermediate alloy, Mg-Ca intermediate alloy, Al-Ti intermediate alloy and Mg-Sr intermediate alloy, is incubated 7 ~ 15min, until alloy removes surface scum after all melting, temperature is risen to 730 ~ 740 DEG C Stop afterwards heating up, then stir, then be cooled to 690 ~ 700 DEG C, stand 4 ~ 8 min, then aluminium alloy is poured into preheating Temperature is natural cooling in 250 ~ 300 DEG C of metal type dies, obtains cast alloy；

4）By step 3）Gained cast alloy carries out heat treatment, and described heat treatment is that cast alloy is carried out at solid solution successively Reason and Ageing Treatment, solid solution temperature is 430 ~ 440 DEG C, and process time is 15 ~ 20 hours, then with 80 ~ 100 DEG C of water quenching Fire is to room temperature；Aging temperature is 220 ~ 260 DEG C, and process time is 16 ~ 24 hours, and then in the air is cooled to room temperature, its Middle solution treatment is carried out under magnesium oxide powder covering.

Beneficial effects of the present invention：

The present invention passes through to introduce appropriate rare earth element Sm, alkaline earth element Ca and Sr and other elements Ag, Sn, Ti, passes through The method of multicomponent microalloying is modified to alloy, and the cast alloy obtaining is carried out heat treatment, prepared by the present invention Mg-Al-Zn alloy there is higher room temperature and Testing Tensile Strength at Elevated Temperature, plasticity has also obtained larger improvement, and microscopic structure Uniformly；The magnesium alloy cost that the present invention provides is relatively low, and melting and Technology for Heating Processing are simple.

Specific embodiment

With reference to specific embodiment, the present invention is further elaborated.

Embodiment 1

A kind of preparation method of heat resistance magnesium alloy as described above, comprises the following steps：

2）By step 1）The pure magnesium ingot that weighs, fine aluminium ingot, pure zinc granule, pure tin grain, fine silver ingot, Mg-Sm intermediate alloy, Mg- Sr intermediate alloy, Mg-Ca intermediate alloy and Al-Ti intermediate alloy drying and preheating 2h under the conditions of 180 DEG C, standby；

3）By step 2）Pure magnesium ingot after preheating, fine aluminium ingot, pure zinc granule, pure tin grain and fine silver ingot are in CO₂+SF₆Mixed gas Protection is lower to melt, and is heated to when 710 DEG C adding Mg-Sm intermediate alloy, Mg-Ca intermediate alloy, Al-Ti intermediate alloy and Mg-Sr Intermediate alloy, is incubated 9min, until alloy removes surface scum after all melting, temperature is risen to and stops after 735 DEG C heating up, so After stir, then be cooled to 700 DEG C, stand 6 min, then aluminium alloy is poured into the metal mold that preheating temperature is 270 DEG C In mould, natural cooling, obtain cast alloy；

4）By step 3）Gained cast alloy carries out heat treatment, and described heat treatment is that cast alloy is carried out at solid solution successively Reason and Ageing Treatment, solid solution temperature is 430 DEG C, and process time is 19 hours, then with 85 DEG C of water quenching to room temperature；When Effect treatment temperature is 220 DEG C, and process time is 22 hours, and then in the air is cooled to room temperature, and wherein solution treatment is in magnesium oxide Powder is carried out under covering, and prevents oxidizing fire.

Embodiment 2

A kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm, each component and its percetage by weight are：Al for 6.12%, Zn is 2.55%, Sm 3.61%, Ag 0.92%, Ca 0.84%, Sr 0.56%, Sn 0.39%, Ti 0.22%, balance of Mg；

2）By step 1）The pure magnesium ingot that weighs, fine aluminium ingot, pure zinc granule, pure tin grain, fine silver ingot, Mg-Sm intermediate alloy, Mg- Sr intermediate alloy, Mg-Ca intermediate alloy and Al-Ti intermediate alloy drying and preheating 2h under the conditions of 190 DEG C, standby；

3）By step 2）Pure magnesium ingot after preheating, fine aluminium ingot, pure zinc granule, pure tin grain and fine silver ingot are in CO₂+SF₆Mixed gas Protection is lower to melt, and is heated to when 705 DEG C adding Mg-Sm intermediate alloy, Mg-Ca intermediate alloy, Al-Ti intermediate alloy and Mg-Sr Intermediate alloy, is incubated 10min, until alloy removes surface scum after all melting, temperature is risen to and stops after 730 DEG C heating up, Then stir, then be cooled to 690 DEG C, stand 4min, then aluminium alloy is poured into the metal mold that preheating temperature is 280 DEG C In mould, natural cooling, obtain cast alloy；

4）By step 3）Gained cast alloy carries out heat treatment, and described heat treatment is that cast alloy is carried out at solid solution successively Reason and Ageing Treatment, solid solution temperature is 435 DEG C, and process time is 18 hours, then with 90 DEG C of water quenching to room temperature；When Effect treatment temperature is 230 DEG C, and process time is 20 hours, and then in the air is cooled to room temperature, and wherein solution treatment is in magnesium oxide Powder is carried out under covering, and prevents oxidizing fire.

Embodiment 3

A kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm, each component and its percetage by weight are：Al for 7.36%, Zn is 2.68%, Sm be 1.97%, Ag be 1.74%, Ca be 1.37%, Sr be 0.47%, Sn be 0.68%, Ti be 0.28%, balance of Mg；

2）By step 1）The pure magnesium ingot that weighs, fine aluminium ingot, pure zinc granule, pure tin grain, fine silver ingot, Mg-Sm intermediate alloy, Mg- Sr intermediate alloy, Mg-Ca intermediate alloy and Al-Ti intermediate alloy drying and preheating 2h under the conditions of 200 DEG C, standby；

3）By step 2）Pure magnesium ingot after preheating, fine aluminium ingot, pure zinc granule, pure tin grain and fine silver ingot are in CO₂+SF₆Mixed gas Protection is lower to melt, and is heated to when 720 DEG C adding Mg-Sm intermediate alloy, Mg-Ca intermediate alloy, Al-Ti intermediate alloy and Mg-Sr Intermediate alloy, is incubated 7min, until alloy removes surface scum after all melting, temperature is risen to and stops after 740 DEG C heating up, so After stir, then be cooled to 700 DEG C, stand 4min, then aluminium alloy is poured into the metal pattern die that preheating temperature is 280 DEG C In tool, natural cooling, obtain cast alloy；

4）By step 3）Gained cast alloy carries out heat treatment, and described heat treatment is that cast alloy is carried out at solid solution successively Reason and Ageing Treatment, solid solution temperature is 435 DEG C, and process time is 17 hours, then with 90 DEG C of water quenching to room temperature；When Effect treatment temperature is 240 DEG C, and process time is 18 hours, and then in the air is cooled to room temperature, and wherein solution treatment is in magnesium oxide Powder is carried out under covering, and prevents oxidizing fire.

Embodiment 4

A kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm, each component and its percetage by weight are：Al for 7.98%, Zn is 1.92%, Sm be 2.45%, Ag be 1.52%, Ca be 1.64%, Sr be 0.19%, Sn be 0.83%, Ti be 0.42%, balance of Mg；

3）By step 2）Pure magnesium ingot after preheating, fine aluminium ingot, pure zinc granule, pure tin grain and fine silver ingot are in CO₂+SF₆Mixed gas Protection is lower to melt, and is heated to when 700 DEG C adding Mg-Sm intermediate alloy, Mg-Ca intermediate alloy, Al-Ti intermediate alloy and Mg-Sr Intermediate alloy, is incubated 13min, until alloy removes surface scum after all melting, temperature is risen to and stops after 730 DEG C heating up, Then stir, then be cooled to 695 DEG C, stand 7min, then aluminium alloy is poured into the metal mold that preheating temperature is 290 DEG C In mould, natural cooling, obtain cast alloy；

4）By step 3）Gained cast alloy carries out heat treatment, and described heat treatment is that cast alloy is carried out at solid solution successively Reason and Ageing Treatment, solid solution temperature is 440 DEG C, and process time is 16 hours, then with 95 DEG C of water quenching to room temperature；When Effect treatment temperature is 250 DEG C, and process time is 16 hours, and then in the air is cooled to room temperature, and wherein solution treatment is in magnesium oxide Powder is carried out under covering, and prevents oxidizing fire.

Embodiment 5

A kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm, each component and its percetage by weight are：Al for 9.07%, Zn is 2.15%, Sm be 3.37%, Ag be 0.39%, Ca be 0.53%, Sr be 0.35%, Sn be 0.47%, Ti be 0.37%, balance of Mg；

3）By step 2）Pure magnesium ingot after preheating, fine aluminium ingot, pure zinc granule, pure tin grain and fine silver ingot are in CO₂+SF₆Mixed gas Protection is lower to melt, and is heated to when 700 DEG C adding Mg-Sm intermediate alloy, Mg-Ca intermediate alloy, Al-Ti intermediate alloy and Mg-Sr Intermediate alloy, is incubated 14min, until alloy removes surface scum after all melting, temperature is risen to and stops after 740 DEG C heating up, Then stir, then be cooled to 700 DEG C, stand 4min, then aluminium alloy is poured into the metal mold that preheating temperature is 300 DEG C In mould, natural cooling, obtain cast alloy；

4）By step 3）Gained cast alloy carries out heat treatment, and described heat treatment is that cast alloy is carried out at solid solution successively Reason and Ageing Treatment, solid solution temperature is 435 DEG C, and process time is 18 hours, then with 95 DEG C of water quenching to room temperature；When Effect treatment temperature is 250 DEG C, and process time is 18 hours, and then in the air is cooled to room temperature, and wherein solution treatment is in magnesium oxide Powder is carried out under covering, and prevents oxidizing fire.

Embodiment 6

A kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm, each component and its percetage by weight are：Al for 10.39%, Zn is 1.87%, Sm be 2.84%, Ag be 0.77%, Ca be 1.14%, Sr be 0.61%, Sn be 0.14%, Ti be 0.14%, balance of Mg；

3）By step 2）Pure magnesium ingot after preheating, fine aluminium ingot, pure zinc granule, pure tin grain and fine silver ingot are in CO₂+SF₆Mixed gas Protection is lower to melt, and is heated to when 720 DEG C adding Mg-Sm intermediate alloy, Mg-Ca intermediate alloy, Al-Ti intermediate alloy and Mg-Sr Intermediate alloy, is incubated 8min, until alloy removes surface scum after all melting, temperature is risen to and stops after 730 DEG C heating up, so After stir, then be cooled to 690 DEG C, stand 7min, then aluminium alloy is poured into the metal pattern die that preheating temperature is 290 DEG C In tool, natural cooling, obtain cast alloy；

4）By step 3）Gained cast alloy carries out heat treatment, and described heat treatment is that cast alloy is carried out at solid solution successively Reason and Ageing Treatment, solid solution temperature is 435 DEG C, and process time is 19 hours, then with 95 DEG C of water quenching to room temperature；When Effect treatment temperature is 230 DEG C, and process time is 21 hours, and then in the air is cooled to room temperature, and wherein solution treatment is in magnesium oxide Powder is carried out under covering, and prevents oxidizing fire.

Comparative example 1

This comparative example Mg-Al-Zn series magnesium alloy is to be grouped into by the group of following percetage by weight：Al for 6.79%, Zn is 2.39%, balance of Mg；Described alloy preparation method is as follows：

It is placed in 200 DEG C of drying baker carrying out according to weight percent content configuration pure magnesium ingot, fine aluminium ingot and pure zinc granule Drying and preheating, preheating time is 2 hours.By the pure magnesium ingot after preheating, fine aluminium ingot, pure zinc granule in CO₂+SF₆Under mixed gas protected Fusing, is incubated 13 minutes, until alloy removes surface scum after all melting, temperature is risen to and stops after 730 DEG C heating up, then Stir, then be down to 695 DEG C about, static 6 minutes, then aluminium alloy is poured in the metal type dies of preheating, metal The preheating temperature of pattern tool is 280 DEG C, obtains cast alloy；Cast alloy is carried out heat treatment, solid solution temperature is 430 DEG C, process time is 19 hours, and hot water is quenched to room temperature, and hot water temperature is 90 DEG C；Aging temperature is 230 DEG C, during process Between be 20 hours, be air cooled to room temperature, wherein solution treatment carries out preventing oxidizing fire under magnesium oxide powder covering.

Comparative example 2

This comparative example Mg-Al-Zn series magnesium alloy is to be grouped into by the group of following percetage by weight：Al for 9.37%, Zn is 2.17%, balance of Mg；Described alloy preparation method is as follows：

It is placed in 200 DEG C of drying baker carrying out according to weight percent content configuration pure magnesium ingot, fine aluminium ingot and pure zinc granule Drying and preheating, preheating time is 2 hours.By the pure magnesium ingot after preheating, fine aluminium ingot, pure zinc granule in CO₂+SF₆Under mixed gas protected Fusing, is incubated 12 minutes, until alloy removes surface scum after all melting, temperature is risen to and stops after 735 DEG C heating up, then Stir, then be down to 700 DEG C about, static 5 minutes, then aluminium alloy is poured in the metal type dies of preheating, metal The preheating temperature of pattern tool is 290 DEG C, obtains cast alloy.Cast alloy is carried out heat treatment, solid solution temperature is 435 DEG C, process time is 17 hours, and hot water is quenched to room temperature, and hot water temperature is 95 DEG C；Aging temperature is 240 DEG C, during process Between be 17 hours, be air cooled to room temperature, wherein solution treatment carries out preventing oxidizing fire under magnesium oxide powder covering.

The present invention contains the Mg-Al-Zn system heat resistance magnesium alloy tensile strength test method of Sm：Sample is according to national standard GB6397-86《Metal stretching experimental sample》It is processed into 5 times of standard tensile specimen；In Japanese Shimadzu AG-I 250kN precision ten thousand Tension test can be carried out, rate of extension is 1mm/min in experimental machine；During drawing by high temperature, 10 minutes to be incubated, then stretched.

Embodiment 1-6 and comparative example 1-2 obtains the room temperature of alloy and 200 DEG C of mechanical property is listed in table 1, can from table To find out, in comparative example 1 and 2, Mg-Al-Zn series magnesium alloy is not added with rare earth element Sm, alkaline earth element Ca and Sr and other yuan When plain Ag, Sn, Ti, the tensile strength of its room temperature, yield strength and percentage elongation are significantly lower than embodiment 1 ~ 6, and alloying element is to magnesium The raising of alloy high-temp mechanical property is especially pronounced.

The mechanical property of table 1 heat resistance magnesium alloy of the present invention

Magnalium zinc series magnesium alloy is one of industrial at present magnesium alloy being most widely used, and this series alloy has excellent Room temperature strength and plasticity, excellent casting and machinability, relatively low cost, Al element is first group of this series alloy Point, it is the important alloying element of magnesium alloy, has big solid solubility in magnesium, both ways, one is to pass through on its invigoration effect surface Form Mg₁₇Al₁₂The second-phase strength of intermetallic compound, two is the solid solution forming solid solution by Al atom in magnesium matrix Strengthening.Mg in magnalium zinc series magnesium alloy₁₇Al₁₂Phase heat stability is poor, is easy to soften so that this series alloy under high temperature High-temperature behavior is poor.Zn has stronger solution strengthening and ageing strengthening effect in the magnesium alloy, and the interpolation of Zn simultaneously can carry Heavy alloyed plasticity.Rare earth element Sm and alkaline earth element Ca, Sr can form some resistant to elevated temperatures intermetallics with Al element Thing, these intermetallic compounds are distributed on crystal boundary, instead of part Mg₁₇Al₁₂Phase, changes Mg₁₇Al₁₂The precipitation state of phase And structure, it additionally is able to crystal grain thinning, delays growing up of crystal grain, improve the percentage elongation of alloy.Ag, Sn, Ti element is equally Improve the important element of magnalium series magnesium alloy heat resistance.

Claims

1. a kind of Mg-Al-Zn system heat resistance magnesium alloy containing Sm is it is characterised in that each component and its percetage by weight are：Al is 2～11%, Zn for 1.5～3%, Sm for 1.8～4%, Ag for 0.2～1.8%, Ca for 0.1～1.9%, Sr for 0.1～0.7%, Sn are 0.1～0.9%, Ti are 0.1～0.5%, balance of Mg.

2. contain as claimed in claim 1 the Mg-Al-Zn system heat resistance magnesium alloy of Sm it is characterised in that each component and its weight hundred Fraction is：Al be 4.79%, Zn be 2.97%, Sm be 2.84%, Ag be 0.92%, Ca be 0.28%, Sr be 0.32%, Sn be 0.25%, Ti is 0.19%, balance of Mg.

3. contain as claimed in claim 1 the Mg-Al-Zn system heat resistance magnesium alloy of Sm it is characterised in that each component and its weight Percent is：Al for 6.12%, Zn for 2.55%, Sm for 3.61%, Ag for 0.92%, Ca for 0.84%, Sr for 0.56%, Sn is 0.39%, Ti are 0.22%, balance of Mg.

4. contain as claimed in claim 1 the Mg-Al-Zn system heat resistance magnesium alloy of Sm it is characterised in that each component and its weight Percent is：Al for 10.39%, Zn for 1.87%, Sm for 2.84%, Ag for 0.77%, Ca for 1.14%, Sr for 0.61%, Sn is 0.14%, Ti are 0.14%, balance of Mg.

5. a kind of preparation method of heat resistance magnesium alloy as claimed in claim 1 is it is characterised in that comprise the following steps：

1）According to above-mentioned percetage by weight weigh pure magnesium ingot, fine aluminium ingot, pure zinc granule, pure tin grain, fine silver ingot, Mg-Sm intermediate alloy, Mg-Sr intermediate alloy, Mg-Ca intermediate alloy and Al-Ti intermediate alloy, standby；

2）By step 1）In the pure magnesium ingot that weighs, fine aluminium ingot, pure zinc granule, pure tin grain, fine silver ingot, Mg-Sm intermediate alloy, Mg-Sr Between alloy, Mg-Ca intermediate alloy and Al-Ti intermediate alloy drying and preheating 2h under the conditions of 180 ~ 200 DEG C, standby；

3）By step 2）Pure magnesium ingot after preheating, fine aluminium ingot, pure zinc granule, pure tin grain and fine silver ingot are in CO₂+SF₆Mixed gas protected Lower fusing, is heated to when 700 ~ 720 DEG C adding Mg-Sm intermediate alloy, Mg-Ca intermediate alloy, Al-Ti intermediate alloy and Mg-Sr Intermediate alloy, is incubated 7 ~ 15min, until alloy removes surface scum after all melting, temperature is risen to and stops after 730 ~ 740 DEG C Heat up, then stir, then be cooled to 690 ~ 700 DEG C, stand 4 ~ 8 min, then aluminium alloy being poured into preheating temperature is In 250 ~ 300 DEG C of metal type dies, natural cooling, obtain cast alloy；

4）By step 3）Gained cast alloy carries out heat treatment, described heat treatment be cast alloy is carried out successively solution treatment and Ageing Treatment, solid solution temperature is 430 ~ 440 DEG C, and process time is 15 ~ 20 hours, then with 80 ~ 100 DEG C of water quenching extremely Room temperature；Aging temperature is 220 ~ 260 DEG C, and process time is 16 ~ 24 hours, and then in the air is cooled to room temperature, wherein solid Molten process is carried out under magnesium oxide powder covers.