Grain refiner for synthesis of aluminium alloy by laser ignited self-propagation and method for preparing the same

Abstract

The invention relates grain refiner used for synthesizing aluminum alloy by laser firing and preparing method. The grain refiner comprises Al, Ti and B. The method comprises the following steps: mixing the Al, Ti, B and TiH2 powers with blending attachment, adding the powders into die and pressing them to preformed sample, after evacuating and filling argon gas, utilizing the laser to carry out self-propagating reaction of preformed sample and get grain refiner. The grain refiner possesses good refining effect and decline-resistant capability. The invention suits for aluminum alloy handling field.

Description

technical field [0001] The invention belongs to the field of metal materials, in particular to a novel grain refiner for aluminum and aluminum alloys and a preparation method. Background technique [0002] At present, grain refinement of aluminum and aluminum alloys contributes to the uniform structure and chemical composition; significantly improves the mechanical properties and processing performance of aluminum materials; it is an important way to improve the quality of aluminum materials. There are many ways to refine grains, but the method of adding nucleating agent has the advantages of high efficiency, low cost and simplicity, and is widely used in modern industrial production. An AlTiB master alloy that can effectively refine aluminum grains is widely used in the aluminum product industry at home and abroad. [0003] The methods used in the preparation of AlTiB master alloys mainly include the following: the aluminothermic reduction of alkali metal fluorides (K2TiF6...

AI Technical Summary

Problems solved by technology

[0004] The refinement effect of salt block agent is unstable and the long-term performance is poor. Due to the serious oxidation and burning of Ti and B elements, the composition is difficult to be strictly controlled, and it is easy to cause casting defects such as slag inclusions and pores in aluminum alloy products, and toxic gases are emitted. , severely corroded equipment, and deteriorated working conditions

The ingot-shaped AlTiB master alloy is much superior to the salt compound refiner, but there are still many problems: the compound phase in the ingot-like master alloy is coarse, and there is a problem of compound specific gravity segregation. After the form is added to the aluminum melt, it is easy to cause TiB 2 、TiAl 3 Inhomogeneous particle distribution, TiB 2 Particles are easy to deposit

Filamentous AlTiB master alloys also have some unsatisfactory disadvantages during use, for example: TiB will be formed during the Al-Ti-B manufacturing process 2 agglomerates or form loose TiB 2 The aggregates cannot be fully decomposed after being added to the melt, and they either deposit at the bottom of the launder or block the filter to affect the refinement effect; TiB 2 The particle size is large, and it is easy to form surface scratches and damage the surface of the pressure roller in aluminum foil and printed substrates. It will also affect some deep-drawing products, such as: scratching the mold, forming scratches and streaks on the surface of the product; some containing Aluminum alloys of Zr and Cr make TiB 2 The particles are cleaned to cause large grains or uneven structure; only 1 to 2% of the compound particles in the master alloy play the role of heterogeneous crystal nuclei, and more than 98% of the compounds have not nucleated, and the nucleation potential of the compound is still far away The metallurgical quality of the AlTiB master alloy is poor, and the content of inclusions is high. After being added to the aluminum and its alloys to be refined, it will pollute the aluminum and its alloys while refining the aluminum grains, resulting in a series of side effect