A kind of aluminum-titanium-boron alloy and its powder metallurgy forming method

Abstract

The invention discloses an Al-Ti-B alloy and a powder metallurgic molding method thereof. The Al-Ti-B alloy comprises 69-73% of Al, 24-28% of Ti and 2-4% of B according to a ratio by weight. The powder metallurgic molding method comprises the following four steps: 1, preparing raw materials, auxiliary materials, tools and equipment; 2, carrying out vacuum induction melting on the alloy; 3, preparing master alloy powder; and 4, carrying out powder metallurgic molding. The Al-Ti-B alloy is low in impurity content, fine in crystalline grains, uniform in components and high in Ti-B content. The powder metallurgic molding method is high in purity, free of pollutants, free of waste gas, easy to control, stable in quality and high in yield rate.

Description

technical field [0001] The invention relates to the field of aluminum alloy forming, in particular to an aluminum-titanium-boron alloy and a powder metallurgy forming method thereof. Background technique [0002] Due to its excellent performance, aluminum alloys are widely used in various fields in actual production and life. Aluminum alloys can be divided into cast aluminum alloys and wrought aluminum alloys, and wrought aluminum alloys can be divided into heat-treated and non-heat-treated wrought aluminum alloys. In order to obtain excellent comprehensive mechanical properties of cast aluminum alloy and non-heat-treated strengthened deformed aluminum alloy, it is necessary to obtain a fine and uniform equiaxed grain structure. There are three main methods of grain refinement for aluminum alloys: (1) controlling the cooling rate of metal solidification; (2) mechanical physical refinement; (3) chemical refinement by adding a grain refiner. So far the most effective and sim...

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Problems solved by technology

Among the relevant patents that have been applied in China, the patent "A Production Process of Aluminum-Titanium-Boron" (application number: 201410180911.7, publication date: 2014-07-30) discloses a production process of aluminum-titanium-boron combined with the reduction method, but In its production process, because there is no vacuum environment, degassing and impurity removal are insufficient; since there is no restriction on the crucible material for smelting, conventional cast iron crucibles may be used, which will make it difficult to control the content of impurity iron. Compared with the original smelting and solidification method, the original grains are not refined enough, which leads to the fact that the final finished Al-Ti-B alloy can provide a small number of nuclei, uneven distribution, and grown grains when used as a grain refiner. The particle size is large, and at the same time, due to the lack of powder metallurgy, the ratio of titanium boron supersaturation cannot be used (if it is supersaturated, it is easy to segregate, which will lead to uneven composition of the intermediate alloy ingot and inaccurate weighing during application), Therefore, the content of titanium and boron is low, that is, the efficiency of the product is low; on the other hand, compared with the conventional method, the method adopted in this invention still produces waste gas and waste residue that are difficult to handle, and because no efficient equipment is used, the entire process is difficult to control. The quality of the final aluminum-titanium-boron alloy is not stable

The patent "A Preparation Method for Al-Ti-B Alloy Ingot" (Application No.: 201510252071.5, Publication Date: 2015-09-02) discloses a method for preparing Al-Ti-B alloy ingots by powder metallurgy, but its The original smelting method is still used, and the material of the smelting crucible is not specified, so the impurity content in the mother alloy liquid is high, the degassing is insufficient, and the foundation of the alloy is poor; due to the low atomization pressure (not refined enough), there is no corresponding Tooling fit (unstable) and no quenching measures (slow cooling speed), the size of the prepared powder is uneven (need to be sieved), the yield is low, and the waste is large. Due to the unreasonable process matching, it is also impossible to use oversaturated The combined formula makes the utilization efficiency of the final product Al-Ti-B alloy low and the quality is unstable. In addition, because there is no cooling process with the furnace after hot pressing, the internal stress of the product is large and uneven, which is easy to cause nucleation during use. Inhomogeneous; in addition, because the alloy liquid may be oxidized to a relatively high degree in the early stage, it is actually meaningless to use vacuum hot isostatic pressing for forming in the end.

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