Aluminum-silicon alloy alterative and manufacturing method thereof

Abstract

The present invention relates to aluminum silicon alloy alterative used for primary crystal silicon in thinning aluminum silicon alloy and method for making same, being characterized by its mass percent constitution as follows: phosphorus: 0.5%-20%; titanium: 3%-5%; carbon: 0.1-0.8%, and the allowance is aluminum. Said preparing process comprises the following steps: (1) homogeneously mixing red phosphorus of 10-45% and powdered aluminum of 55-90%, based on the weight of the mixture; (2) compacting the mixing powder mentioned above into blocks; (3) synthesizing aluminum-phosphorus alloy by self spreading at vacuum or under inert atmosphere; (4)block-compacting again after pulverizing and ball-milling aluminum-phosphorus alloy prepared in step (3); (5) getting, through weighing, activated char and potassium fluotitanate powder, homogeneously mixing them and block-compacting, with a mass ratio of 7-25 of titanium to carbon; (6) melting commercial-purity aluminum and adding, in sequences, mixing powder compact of activated char and potassium fluotitanate, compact of aluminum-phosphorus alloy therein, casting it into ingots or extruding it into wires after stirring it to complete fusion.The alloy in accordance with the present invention doesn't make pollutions during its preparing and using course; can be added to a launder as aluminum-titanium-boron alloy, wherein the deterioration process is simple and the alloy is added in a normal casting process; and the deterioration temperature is low, deterioration effect is stable and long acting.

Description

technical field [0001] The invention relates to an aluminum-silicon alloy modification agent for refining primary silicon in an aluminum-silicon alloy and a preparation method thereof. Background technique [0002] Hypereutectic / eutectic Al-Si alloy has a small linear expansion coefficient, light density, good fluidity, thermal crack resistance, excellent wear resistance and corrosion resistance, and is used in the manufacture of internal combustion engine pistons and automotive swash plate compressors High quality material for swash plate and pistons. However, in the conventional casting structure of this alloy, the primary Si phase in the shape of coarse plates, polygons, and five-lobed stars severely splits the matrix structure, which not only reduces the mechanical properties of the alloy, but also seriously deteriorates the casting properties of the alloy, affecting the The practical application of alloys. How to better refine and modify the primary Si phase is the ke...

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Problems solved by technology

However, there are many problems in the use of these above-mentioned modifiers: (1) For the red phosphorus composite modifier, the red phosphorus flash point is 240 ° C, and there are potential safety hazards in the transportation and storage process; the reaction is violent during the addition process, producing toxic pentoxide Diphosphorus gas, polluting the environment; phosphorus absorption rate is low and difficult to control

(2) Phosphate-salt compound modificator also produces harmful gas and causes serious environmental pollution; produces a large amount of reaction slag, corrodes the furnace lining, and increases aluminum consumption; the absorption rate of phosphorus is limited by the process conditions, the metamorphic effect is unstable, and the scrap rate is high

(3) Cu-P intermediate alloy has a high melting point and is difficult to melt after adding; it has a high density and is easy to segregate, so it is not suitable for static furnace production (domestic production situation), only suitable for induction furnace production; at the same time, it also increases the Cu content in the alloy, which is Not suitable for alloys sensitive to Cu-containing requirements

Some people in China have also developed an Al-P master alloy containing AlP prefabricated crystal nuclei. However, this alloy uses AlP, a highly toxic drug, as a raw material, and there are certain safety problems in the production process.

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