CN103305730A - Novel Al-Si-Mg-Cu-Sr cast alloy - Google Patents

Abstract

The invention discloses a novel Al-Si-Mg-Cu-Sr cast alloy. For the Al-Si-Mg-Cu-Sr cast alloy, in an as-caste state, the tensile strength is between 245 and 275Mpa, and the extensibility is between 5 and 8 percent; in a T6 state, the tensile strength is between 355 and 385Mpa, and the extensibility is between 9.5 and 14 percent. The novel Al-Si-Mg-Cu-Sr cast alloy breaks through the bottleneck that a cast alloy of a similar grade is low in mechanical properties, and the high strength and extensibility of the novel Al-Si-Mg-Cu-Sr cast alloy can meet production requirements for components of brackets, intake manifolds and the like, and can meet requirements on such material in the automotive industry and other fields.

Description

A kind of new A l-Si-Mg-Cu-Sr casting alloy

Technical field

The invention belongs to the nonferrous materials preparing technical field, relate to a kind of Al-Si-Mg-Cu-Sr cast aluminium alloy of high comprehensive performance.

Background technology

Aluminium alloy compare with iron and steel have the specific tenacity height, specific rigidity height, advantage such as thermal conductivity is good, solidity to corrosion is good, therefore aluminium alloy is able to a large amount of promotion and application at space flight and aviation industry, bullet train, automotive industry and other industrial circles, is desirable lightweight material.

The main component of cast aluminium alloy ZL102 is Si10.0～13.0; Fe≤0.7; Cu≤0.3; Mn≤0.5; Mg≤0.1; Zn≤0.1; Ti≤0.20, its as cast condition tensile strength requires σ b 〉=145MPa, unit elongation δ 〉=4%.The present invention improved in a basic enterprising step of this alloy, had obtained the better alloy material of performance.

Summary of the invention

The object of the present invention is to provide a kind of new A l-Si-Mg-Cu-Sr casting alloy, this alloy has added 0.01%～0.02% alterant element strontium, improved with thick needle-like or lamellar morphology exists and the Eutectic Silicon in Al-Si Cast Alloys of seriously isolating matrix, composition is more even, performance is more stable, and its surface presents fine and closely woven fish scale shape surface.

The objective of the invention is to be achieved through the following technical solutions:

A kind of new A l-Si-Mg-Cu-Sr casting alloy, composition is as follows

。

The preparation method of above-mentioned alloy is as follows:

⑴ take by weighing raw materials such as required commercial-purity aluminium, industrial silicon, MAGNESIUM METAL, metallic copper, aluminium strontium master alloy by the alloying constituent requirement, and all material is carried out thermal pretreatment.

⑵ add commercial-purity aluminium, the industrial silicon that preheating is good among the step ⑴ in smelting furnace, the igniting heat temperature raising.

⑶ after treat institute to add raw material all fusing is finished, adjust temperature to 740～760 ℃, preheating is good among the step ⑴ MAGNESIUM METAL, metallic copper are pressed into aluminium liquid bottom, fully stirred 10 minutes.

⑷ when temperature reached 730～750 ℃ of left and right sides, the last marine rainbow light metal flux HGJ-2 of the factory aluminium alloy that uses duster to add gross weight 0.1%～0.2% did not have sodium refining slag-cleaning agent, and operating process removes the gred.

⑸ after slagging-off is finished, the aluminium strontium master alloy that preheating is good among the step ⑴ is dropped in the stove, fully stirred 8～10 minutes.

⑹ adjust temperature to 710～730 ℃, feeds nitrogen in alloy melt, carries out the degas operation process, and the degasification time is 40～60 minutes.

⑺ alloy melt left standstill 15 minutes, and during 680～700 ℃ of temperature of control, the casting ingot casting gets new A l-Si-Mg-Cu-Sr casting alloy.

Advantage of the present invention and positively effect are:

1, the present invention is on the cast aluminium alloy basis of original trade mark ZL102, to in addition strict control of composition, make that alloying constituent is more even, performance is more stable, its surface presents fine and closely woven fish scale shape surface, in its preparation process, added 0.01%～0.02% alterant element strontium, improved with thick needle-like or lamellar morphology exists and the Eutectic Silicon in Al-Si Cast Alloys of seriously isolating matrix.

2, the α of Sr (Al) dendritic growth of the present invention's interpolation has remarkable influence, Sr can make α (Al) dendrite quantity increase, and can make a dendrite when going bad obviously shorten little, and secondary dendrite also improves and diminishing, after heat treatment, silicon is tiny point-like or spherical mutually, thereby has guaranteed Mg ₂Si strengthens the effect of body and the plasticity of aluminum substrate is not fully exerted, thereby has improved the performance of aluminium alloy.

3, Al-Si-Mg-Cu-Sr alloy casting state tensile strength provided by the invention is between 245～275Mpa, unit elongation is between 5%～8%, under the T6 state between tensile strength 355～385Mpa, unit elongation is between 9.5%～14%, broken through the not high bottleneck of similar trade mark cast aluminium alloy mechanical property, the intensity that it is higher and unit elongation can satisfy the production requirement of component such as support class and intake manifold, can satisfy automobile industry and other field to the demand of such material.

4, Al-Si-Mg-Cu-Sr alloy of the present invention is a kind of brand-new aluminum alloy materials, and materials such as alternative cast iron, original grade aluminium alloy are used for the production of parts such as automobile generating machine support, engine support, intake manifold, power steering system.

Description of drawings

Fig. 1 is not for adding the Al-Si-Mg-Cu alloy high power metallographic structure of strontium, the visible significantly Eutectic Silicon in Al-Si Cast Alloys of bodkin shape;

Fig. 2 is the Al-Si-Mg-Cu-Sr alloy high power metallographic structure under the as cast condition, and the Eutectic Silicon in Al-Si Cast Alloys of bodkin shape has become rod-short or spherulitic;

Fig. 3 is the Al-Si-Mg-Cu-Sr alloy high power metallographic structure after the thermal treatment, and silicon is tiny point-like or spherical mutually.

Embodiment

Below in conjunction with embodiment, the present invention is further described, and following embodiment is illustrative, is not determinate, can not limit protection scope of the present invention with following embodiment.

The HGJ-2 type that the last marine rainbow light metal flux factory that following examples are used produces does not have sodium refining slag-cleaning agent, and the no sodium refining slag-cleaning agent that other producers originate also can be realized the present invention, and no sodium refining slag-cleaning agent also is called no sodium slag-cleaning agent.

A kind of new A l-Si-Mg-Cu-Sr casting alloy, main chemical compositions such as following table 1:

The preparation method of above-mentioned alloy is as follows:

⑴ take by weighing raw materials such as required commercial-purity aluminium, industrial silicon, MAGNESIUM METAL, metallic copper, aluminium strontium master alloy by the alloying constituent requirement, and all material is carried out thermal pretreatment.

⑵ add commercial-purity aluminium, the industrial silicon that preheating is good among the step ⑴ in smelting furnace, the igniting heat temperature raising.

⑶ after treat institute to add raw material all fusing is finished, adjust temperature to 740～760 ℃, preheating is good among the step ⑴ MAGNESIUM METAL, metallic copper are pressed into aluminium liquid bottom, fully stirred 10 minutes.

⑷ when temperature reached 730～750 ℃ of left and right sides, the last marine rainbow light metal flux HGJ-2 of the factory aluminium alloy that uses duster to add gross weight 0.1%～0.2% did not have sodium refining slag-cleaning agent, and operating process removes the gred.

⑸ after slagging-off is finished, the aluminium strontium master alloy that preheating is good among the step ⑴ is dropped in the stove, fully stirred 8～10 minutes.

⑹ adjust temperature to 710～730 ℃, feeds nitrogen in alloy melt, carries out the degas operation process, and the degasification time is 40～60 minutes.

⑺ alloy melt left standstill 15 minutes, and during 680～700 ℃ of temperature of control, the casting ingot casting gets new A l-Si-Mg-Cu-Sr casting alloy.

Embodiment 1

A kind of new A l-Si-Mg-Cu-Sr casting alloy, the preparation method is as follows:

⑴ take by weighing commercial-purity aluminium 15745Kg, industrial silicon 2070Kg, MAGNESIUM METAL 75Kg, metallic copper 70Kg, aluminium strontium master alloy (AlSr10) 40Kg, and raw material gross weight 18000Kg dropped into all raw materials in 250 ℃ the constant temperature preheating and drying stove dry 2.5 hours.

⑵ add good commercial-purity aluminium, the industrial silicon of preheating in 20T accumulation of heat smelting furnace, 750 ℃ of temperature are set, the igniting heat temperature raising.

⑶ after treat institute to add raw material all fusing is finished, adjust about temperature to 750 ℃, preheating is good among the step ⑴ MAGNESIUM METAL, metallic copper are pressed into aluminium liquid bottom, fully stirred 10 minutes.

⑷ when temperature reached 740 ℃ of left and right sides, the last marine rainbow light metal flux HGJ-2 of the factory aluminium alloy that uses duster to add gross weight 28Kg did not have sodium refining slag-cleaning agent, and operating process removes the gred.

⑸ after slagging-off is finished, the aluminium strontium master alloy that preheating is good among the step ⑴ is dropped in the stove, fully stirred 10 minutes.

⑹ adjust about temperature to 720 ℃, adjusts nitrogen flow, carries out the degas operation process, and the degasification time is 50 minutes.

⑺ alloy melt left standstill 15 minutes, during 680 ℃ of temperature of control, and the casting ingot casting.

Embodiment 2

A kind of new A l-Si-Mg-Cu-Sr casting alloy, the preparation method is as follows:

⑴ take by weighing commercial-purity aluminium 14441Kg, industrial silicon 1900Kg, MAGNESIUM METAL 66Kg, metallic copper 60Kg, aluminium strontium master alloy (AlSr10) 33Kg, and raw material gross weight 16500Kg dropped into all raw materials in 250 ℃ the constant temperature preheating and drying stove dry 2.5 hours.

⑵ add good commercial-purity aluminium, the industrial silicon of preheating in 20T accumulation of heat smelting furnace, 750 ℃ of temperature are set, the igniting heat temperature raising.

⑶ after treat institute to add raw material all fusing is finished, adjust about temperature to 750 ℃, preheating is good among the step ⑴ MAGNESIUM METAL, metallic copper are pressed into aluminium liquid bottom, fully stirred 10 minutes.

⑷ when temperature reached 740 ℃ of left and right sides, the last marine rainbow light metal flux HGJ-2 of the factory aluminium alloy that uses duster to add gross weight 25Kg did not have sodium refining slag-cleaning agent, and operating process removes the gred.

⑸ after slagging-off is finished, the aluminium strontium master alloy that preheating is good among the step ⑴ is dropped in the stove, fully stirred 10 minutes.

⑹ adjust about temperature to 720 ℃, adjusts nitrogen flow, carries out the degas operation process, and the degasification time is 50 minutes.

⑺ alloy melt left standstill 15 minutes, during 680 ℃ of temperature of control, and the casting ingot casting.

Claims (1)

1. new A l-Si-Mg-Cu-Sr casting alloy, it is characterized in that: composition is as follows

。

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