CN103757503A - Method for increasing electric conductivity of Al-Mg-Si alloy - Google Patents

Abstract

The invention discloses a method for increasing the electric conductivity of an Al-Mg-Si alloy. The method comprises the following steps: (1) reasonably blending chemical components, and controlling Fe to be less than 0.2%, Si to be less than or equal to 0.4% and Mg to be less than or equal to 0.55%; and (2) controlling the content of elements such as Cr, Mn and Ti; (3) refining the cast structure of a cast rod so as to enable the grain size of the cast rod to be less than two-grade; (4) using Al-Ti-B for refining the cast structure; and (5) improving the in-P purity of the cast rod, and controlling H to be less than 0.18ml/100gAl, the content of oxide inclusion with the particle size of above 10 micrometers to be less than 5%, and the content of the oxide inclusion with the particle size of above 5 micrometers to be less than 50%. The method has the beneficial effects that the inner structure of the aluminium alloy is ordered by controlling the content of each element in the aluminium alloy, the elements can be chemically combined with certain elements unfavorable to electric conductivity in the step B to form an insoluble compound, and the insoluble compound is separated out from a solid solution, thus the electric conductivity of the alloy is improved.

Description

A kind of method that improves Al-Mg-Si alloy conductive rate

Technical field

A kind of method that the present invention relates to the Al-Mg-Si of raising alloy conductive rate, belongs to metallurgical technology field.

Background technology

For aluminium alloy, along with the raising of the alloy element content such as Mg, Si, its peak value aging strength rises and electric conductivity decline, has limited the further application of this alloy in electro-conductive material field; Improve aluminium alloy conductivity and can reduce the constituent contents such as Mg, Si, Fe by controlling metallurgical quality, and adopt overaging to process, for example the mode of T7 state occurs.But to require the aluminium alloy of specific mechanics performance level and electric conductivity simultaneously, only have by controlling online and later stage thermal treatment process and realize.Precipitation strength type aluminium alloy for certain ingredients scope, come from the precipitated phase that forms in design of alloy and hot-work history and segregation phase amount, configuration alloy electric conductivity has material impact, wherein the solid solution effect of strengthening phase and quantity, yardstick and the distribution of precipitated phase are to control the principal element of alloy strength, their On Dislocation Motions form completes a business transaction, obstacle and retardation, is conducive to alloy and obtains higher-strength; Meanwhile, along with precipitate volume fraction increases and disperse distribution, cause unbound electron motion space or mean free path to diminish gradually, alloy conductive rate declines; And Grain Boundary Segregation phase amount and morphological specificity can be the sexual factors that improves that affects alloy conductive rate.Therefore how effectively to control strengthening phase in alloy hot-work history and separate out quantity, and the metallurgy feature of crystal boundary and the distribution of intracrystalline precipitated phase, configuration and differentiation thereof in Precipitation process, for obtaining high conductivity and suitably intensity is most important.

Summary of the invention

In order to overcome above-mentioned defect, the invention provides a kind of method of the Al-Mg-Si of raising alloy conductive rate.

To achieve these goals, technical scheme of the present invention is: a kind of method of the Al-Mg-Si of raising alloy conductive rate, and described step is:

1), rational allocation chemical composition: control Fe<0.2%, Si≤0.4%, Mg≤0.55%;

2), control the content of the elements such as Cr, Mn, Ti: wherein control Gr<0.03%, Mn<0.04%, Ti<0.03%, other impurity element monomer content <0.03%, impurity summation <0.10%;

3), the cast structure of refinement casting rod, make its grain fineness number <2 level;

4), use Al-Ti-B refinement cast structure;

5), improve the interior P clarity of casting rod, control H<0.18ml/100gAl, content <5% more than oxide inclusion granularity 10 μ, content <50% more than 5 μ.

Further, the Mg+Si<0.9% in described step 1).

The invention has the beneficial effects as follows: by controlling the content of each element in aluminium alloy, make the ordering of aluminium alloy inner structure, by B in step, can form insoluble compound with some the element chemical combination that is unfavorable for electric conductivity, from sosoloid, separate out, and then promoted the electric conductivity of alloy.

Embodiment

Below in conjunction with specific embodiment, the present invention is described further.

Embodiment 1

Improve a method for Al-Mg-Si alloy conductive rate, described step is:

1), rational allocation chemical composition: control Fe 0.4%, Si 0.4%, Mg 0.45%;

2), control the content of the elements such as Cr, Mn, Ti: wherein control Gr 0.02%, Mn 0.03%, Ti 0.02%, other impurity element monomer content 0.02%, impurity summation 0.09%;

3), the cast structure of refinement casting rod, make its grain fineness number <2 level;

4), use Al-Ti-B refinement cast structure;

5), improve the interior P clarity of casting rod, control H<0.18ml/100gAl, content <5% more than oxide inclusion granularity 10 μ, content <50% more than 5 μ.

The comparison of alloy conductive rate:

?	Electric conductivity
		Untreated alloy	56.5
The inventive method was processed alloy	62.3

Embodiment 2

Improve a method for Al-Mg-Si alloy conductive rate, described step is:

1), rational allocation chemical composition: control Fe 0.35%, Si 0.32%, Mg 0.47%.

2), control the content of the elements such as Cr, Mn, Ti: wherein control Gr 0.025%, Mn 0.035%, Ti 0.025%, other impurity element monomer content 0.025%;

3), the cast structure of refinement casting rod, make its grain fineness number <2 level;

4), use Al-Ti-B refinement cast structure;

5), improve the interior P clarity of casting rod, control H<0.18ml/100gAl, content <5% more than oxide inclusion granularity 10 μ, content <50% more than 5 μ.

The comparison of alloy conductive rate:

?	Electric conductivity
		Untreated alloy	56.5
The inventive method was processed alloy	61.8

Technical scheme of the present invention is not limited to the restriction of above-mentioned specific embodiment, and the technology distortion that every technical scheme according to the present invention is made, within all falling into protection scope of the present invention.

Claims (2)

1. a method that improves Al-Mg-Si alloy conductive rate, is characterized in that: described step is:

1), rational allocation chemical composition: control Fe<0.2%, Si≤0.4%, Mg≤0.55%;

2), control the content of the elements such as Cr, Mn, Ti: wherein control Gr<0.03%, Mn<0.04%, Ti<0.03%, other impurity element monomer content <0.03%, impurity summation <0.10%;

3), the cast structure of refinement casting rod, make its grain fineness number <2 level;

4), use Al-Ti-B refinement cast structure;

5), improve the interior P clarity of casting rod, control H<0.18ml/100gAl, content <5% more than oxide inclusion granularity 10 μ, content <50% more than 5 μ.

2. the method for raising Al-Mg-Si alloy conductive rate according to claim 1, is characterized in that: the Mg+Si<0.9% in described step 1).