CN101775526A - AL-Cr binary intermediate alloy and preparation method thereof - Google Patents

Abstract

The invention relates to an Al-Cr binary intermediate alloy and a preparation method thereof. The Al-Cr binary intermediate alloy comprises the following components in percentage by weight: 70-90 percent of Al and 10-30 percent of Cr. The invention has the advantages that the content of Cr in the intermediate alloy is largely improved, the amplification thereof reaches 200-600 percent, and the service efficiency of the intermediate alloy is improved; the smelting of the Al-Cr binary intermediate alloy turns simple and easy and saves energy consumption with the whole smelting time of 45-50 minutes, thus the smelting time is greatly shortened and 400 KW/h of electricity can be saved every 100 kilograms of the alloy; and compared with a Cu-Cr alloy, the Al-Cr alloy can play the role of a modificator in the smelting of yellow brass for refining tissue crystal grains and enhancing the material properties.

Description

Al-Cr binary master alloy and preparation method thereof

Technical field

The present invention relates to the alloy melting technical field, specifically a kind of Al-Cr binary master alloy and preparation method thereof in the adding technology of Cr element in the MBA-2 brass material.

Background technology

The Cr element exists with the simple substance particle form in brass, in complex brass, add Cr and can increase substantially the material wear-resistant performance, but the fusing point of Cr is up to 1857 ℃, with MBA-2 material zinc content be that the temperature head of 1185 ℃ of boiling points of brass of 30% reaches 672 ℃, the MBA-2 material can not continue temperature raising after reaching boiling point, the Cr element is difficult to realize the alloying of material in the temperature below 1185 ℃, causes the Cr element to be difficult to fusing, and the interpolation of Cr in brass material be difficulty very.

MBA-2 belongs to the third generation material in the automobile synchronizer tooth ring material, and the material wear-resistant performance is superior, except that the fundamental element Cu, the Zn that contain market brass, also contains strengthening elements such as Al, Mn, Si, Ni, Pb, Cr in this material component; Compare with elements such as Al, Mn, Si, Ni, Pb, the fusing point of Cr element is too high.The addition means of general high-melting-point element is the way interpolation of fritting copper base binary alloy in the copper-based material, this kind method is still very difficult for the interpolation of Cr, its reason has 2 points: the one, and the component concentration of Cr is too low in the Cu-Cr master alloy, general content only 5%, for reaching the target value of material predetermined content, need to use a large amount of Cu-Cr master alloys like this; It two is that Cu-Cr master alloy melting technology is very complicated: need earlier Cu is heated to 1350～1400 ℃, the Cu-Mg alloy deoxidation of copper liquid, Cr is crushed to the lumpiness of 2～5mm and wraps and be pressed in the copper liquid in batches with Copper Foil, every stove Cu-Cr master alloy smelting time reaches 4～5 hours, smelting efficiency is very low, the material scaling loss is bigger, and the Cu-Cr master alloy that this method obtains needs to add in advance in use, can not be as the copper alloy alterant, when material solidification as crystallization nuclei, play the effect of crystal grain thinning, so material property will be subjected to certain influence.

Summary of the invention

The objective of the invention is to develop a kind of Cr of increasing substantially element adding efficient, simplify master alloy melting technology, shorten the Al-Cr binary master alloy and preparation method thereof of the smelting time of master alloy.

The MBA-2 material comprises following chemical element:

Cu、Al、Mn、Si、Ni、Fe、Pb、Cr、Zn

Remove fundamental element Cu, the Zn of brass, alloying element is divided into two groups, promptly Al, Mn, Si, Ni, Fe, Pb be as a group element, in proportion the melting master alloy; In addition, the Al element is reserved certain share and Cr and is formed Al-Cr binary master alloy separately, and described reserved share is 50～60% of the required Al total mass of preparation MBA-2 material.

Described Al-Cr binary master alloy, its weight percentages of components is as follows:

Al 70-90

Cr 10-30。

A kind of preparation method of Al-Cr binary master alloy, its step is as follows:

1. get Cr piece and Al ingot by above-mentioned part by weight, Cr piece lumpiness is crushed in the 30mm, gets the Al ingot of 1/3 weight and puts into electric furnace intensification fusing;

2. when Al liquid color is turned white, when promptly temperature is more than 1250 ℃, add 1. gained Cr piece of step in batches, and stir, confirm that Cr all melts the back and adds 1. residual A l ingot of step, continue to heat up, adjust temperature to 1300～1350 ℃, stir with stirring rod;

3. be casting after the slagging-off.

The advantage of Al-Cr binary master alloy of the present invention and preparation method thereof is:

(1) the present invention has increased substantially the content of Cr in the master alloy, has improved the service efficiency of master alloy; And brass add the Cr method, the content of Cr only can reach 5% in the Cu-Cr alloy, the adding of too high Cr will cause Cr to be difficult to fusing and absorb; Behind Al-Cr alloy replacing Cu-Cr alloy, the content of Cr reaches 10-30% in the alloy, and the content increasing degree of Cr reaches 200-600%, and result of use improves very obvious;

(2) melting of Al-Cr master alloy becomes easily simple, energy efficient: the melting of Cu-Cr alloy need through material pulverize, fine particle Cr is with processes such as the adding fusing of the fusing temperature control of Copper Foil parcel, electrolytic copper, copper fusing deoxidation, Cr and stirrings, the smelting time of Cu-Cr master alloy needs 4～5 hours, the melting technology complexity, smelting time is long, the energy consumption of bringing thus is big, and the material scaling loss is big; After adopting the Al-Cr alloy, Cr only needs its lumpiness of appropriateness control, alloy feeds intake and melts no particular requirement, only needs before pouring into a mould to check that the melting conditions of Cr and temperature adjustment stirring get final product, and Al and Cr carry out alloying reaction during material melts, this reaction belongs to thermopositive reaction, reaction beginning back melt temperature improves rapidly, has greatly promoted the fusing of Cr, and whole smelting time has only 45～50 minutes, shortened the smelting time of alloy greatly, per hundred kilograms of alloys can be saved about 400 degree of power consumption;

(3) with Cu-Cr alloy phase ratio, the Al-Cr alloy can play the effect of alterant in the brass melting, and thinning microstructure crystal grain improves material property.Cu-Cr alloy material fusing point height, because it is little to contain the Cr ratio, add-on is big, can only add with other alloy material during the melting of MBA-2 material, this adding mode does not have the effect (going bad) of crystallization nuclei; And the Al-Cr alloy addition is low, can add at last during melting, the dystectic free Cr particle of part can play the effect of crystallization nuclei in the material solidification process, has increased the quantity of crystal grain widely, crystal grain thinning degree grade, thus every performance of material improved.

Embodiment

Embodiment one

A kind of Al-Cr binary master alloy, its weight percentages of components is as follows:

Al 80

Cr 20。

A kind of preparation method of Al-Cr binary master alloy, its step is as follows:

1. get Cr piece and Al ingot by above-mentioned part by weight, Cr piece lumpiness is crushed in the 30mm, gets the Al ingot of 1/3 weight and puts into electric furnace intensification fusing;

2. when Al liquid color is turned white, when promptly temperature is more than 1250 ℃, add 1. gained Cr piece of step in batches, and stir, confirm that Cr all melts the back and adds 1. residual A l ingot of step, continue to heat up, adjust temperature to 1300 ℃, stir with stirring rod;

3. be casting after the slagging-off.

Embodiment two

A kind of Al-Cr binary master alloy, its weight percentages of components is as follows:

Al 90

Cr 10。

A kind of preparation method of Al-Cr binary master alloy, its step is as follows:

1. get Cr piece and Al ingot by above-mentioned part by weight, Cr piece lumpiness is crushed in the 30mm, gets the Al ingot of 1/3 weight and puts into electric furnace intensification fusing;

2. when Al liquid color is turned white, when promptly temperature is more than 1250 ℃, add 1. gained Cr piece of step in batches, and stir, confirm that Cr all melts the back and adds 1. residual A l ingot of step, continue to heat up, adjust temperature to 1350 ℃, stir with stirring rod;

3. be casting after the slagging-off.

Embodiment three

A kind of Al-Cr binary master alloy, its weight percentages of components is as follows:

Al 70

Cr 30。

A kind of preparation method of Al-Cr binary master alloy, its step is as follows:

1. get Cr piece and Al ingot by above-mentioned part by weight, Cr piece lumpiness is crushed in the 30mm, gets the Al ingot of 1/3 weight and puts into electric furnace intensification fusing;

2. when Al liquid color is turned white, when promptly temperature is more than 1250 ℃, add 1. gained Cr piece of step in batches, and stir, confirm that Cr all melts the back and adds 1. residual A l ingot of step, continue to heat up, adjust temperature to 1320 ℃, stir with stirring rod;

3. be casting after the slagging-off.

The present invention is not limited to above embodiment according to the weight percent proportioning difference of Al-Cr, can realize a plurality of embodiment in allowed limits.

Claims (2)

1. Al-Cr binary master alloy, it is characterized in that: its weight percentages of components is as follows:

Al 70-90

Cr 10-30。

2. the preparation method of an Al-Cr binary master alloy, it is characterized in that: its step is as follows:

1. take by weighing Cr piece and Al ingot by weight percentages of components, Cr piece lumpiness is crushed in the 30mm, gets the Al ingot of 1/3 weight and puts into electric furnace intensification fusing;

2. when Al liquid color is turned white, when promptly temperature is more than 1250 ℃, add 1. gained Cr piece of step in batches, and stir, confirm that Cr all melts the back and adds 1. residual A l ingot of step, continue to heat up, adjust temperature to 1300～1350 ℃, stir with stirring rod;

3. be casting after the slagging-off.