Preparation method of Al5Ti1B intermediate alloy

Abstract

The invention provides a preparation method of an Al5Ti1B intermediate alloy, comprising the following steps of: uniformly mixing the following components in percent by weight: 25 percent-30 percent of KBF4, 30 percent-60 percent of K2TiF6, 10 percent-30 percent of pure aluminum powder and 0 percent-10 percent of pure titanium powder; carrying out cold pressing on the uniformly mixed powder to be a precast block with the density of 50 percent-60 percent by a hydraulic machine and drying for 2 hours at 100 DEG C in a blast drying box; melting aluminum and raising the temperature to 800 DEG C-850 DEG C; pressing the dried precast block into aluminum melt by using a phosphorizer, wherein the weight ratio of the precast block accounts for 30 percent-45 percent; and standing for 20-40 minutes, stirring for 5-10 minutes, slagging-off and pouring and moulding. The invention can realize obviously controlling reaction velocity in the early period of the reaction, quickening the reaction progress in the middle period of the reaction, and reducing fluoride salt by-products in the later period of the reaction. The prepared intermediate alloy has the characteristics that the phase dimension of the Al3Ti is about 20 mu m, the dimensional homogeneity is good, the intermediate alloy are all in block shapes, and TiB2 particles are fine and are uniform in dispersion.

Description

technical field [0001] The invention relates to a method for preparing a metal material. In particular, it is a method for preparing Al5Ti1B master alloy for refining aluminum and its alloys. Background technique [0002] Aluminum is the non-ferrous metal material with the largest output and the widest application range in the world today. Its consumption is second only to steel and is widely used in various sectors of the national economy. However, the strength and hardness of pure aluminum are low, which limits its application range. , so methods such as alloying and grain refinement are usually used to improve its strength and hardness. Especially the development of aluminum can industry and aluminum foil industry requires aluminum and its alloys to have high purity, good ductility and fine grains, which also makes the grain refinement industry of aluminum and its alloys develop rapidly. [0003] Among many grain refinement methods, grain refiners can easily and effecti...

AI Technical Summary

Problems solved by technology

There are mainly the following problems in the preparation of master alloys by this method: (1) a large amount of fluorine salt is added to the melt, and the reaction is extremely violent at the initial stage of the reaction, and the metal elements are oxidized and burned seriously, resulting in a decrease in the yield of Ti and B elements; (2) In the middle stage of the reaction, because the fluoride salt with low density and not wetted with the Al melt floats above the Al liquid and delaminates with the aluminum liquid, the reaction proceeds slowly; (3) In the late stage of the reaction, the reaction by-products The proportion is large, accounting for one-third of the melt; (4) uneven heat release before and after the reaction, resulting in Al 3 The size of the Ti phase is significantly different, and the appearance is often thick and long, which seriously affects the refinement effect

To solve these problems, Yücel Birol uses boron content much larger than KBF 4 Na 2 B 4 o 7 To reduce the total amount of fluorine salts and ease the reaction rate, but the generated by-products are very viscous, which reduces the fluidity of the melt on the one hand and makes it difficult to cast the melt; on the other hand, the viscous salts wrap a part of Al 3 Ti, leading to a decrease in Ti yield

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