Method for improving Al-Zn-Mg-Cu series alloy melt purity degree

Abstract

The invention discloses a method for improving Al-Zn-Mg-Cu series alloy melt purity degree. The method comprises the following steps that a raw material of aluminum alloy is melted to obtain a melt, a refining agent is prepared, the refining agent is divided into N parts, each part is wrapped by aluminum foil, N refining ladles are obtained, and are put into the melt, the melt is subjected to vacuum refining, a fusing agent wrapped by the aluminum foil is put into the melt, the fusing agent wrapped by the aluminum foil is pressed into the position with the distance, away from the melt liquid face, being 0.5 to 0.7 time of the melt depth, the fusing agent is rotated until the fusing agent is melted, and natural cooling is carried out until the room temperature is 20 to 25 DEG C. MgO powder with the purity larger than 99.7% is selected in the refining agent to serve as one part of the refining agent, Mg is the component is the composition alloy, the alloy is not polluted, the too fast reaction between C2C16 and melt can be reduced, refining smoke is restrained, the environment pollution is reduced, and the quality of an aluminum alloy cast ingot produced through the technology can reach AAA level flaw detection standard.

Description

technical field [0001] The invention belongs to the technical field of aluminum alloy smelting, and specifically relates to a method for improving the purity of an Al-Zn-Mg-Cu alloy melt. Background technique [0002] Al-Zn-Mg-Cu series age-hardening alloy is a high-strength aluminum alloy with low density, high strength, high fracture toughness and high transverse performance, and has become a new structural material for military and aerospace industries. Due to its harsh service conditions, the structure of the finished product is not allowed to have defects such as cracks, pores, oxide film, porosity, and coarse grain rings, which requires higher purity of the alloy melt before casting than ordinary aluminum alloys. Melt purity issues include gas contamination, inclusions. Cover with flux during melting to reduce oxidative gettering. Flux refining achieves the effect of reducing inclusions by adsorbing and dissolving oxidized inclusions in the melt. Commonly used refin...

AI Technical Summary

Problems solved by technology

C 2 Cl 6 The decomposition product is Cl 2 and C, which produces pure Cl 2 It is the refining agent with the best degassing and slag removal effect. A small amount of nano-scale C plays a role in modification and does not pollute the alloy, but C 2 Cl 6 The reaction with alloy aluminum liquid is too violent, and it is necessary to add a refining agent (buffer) that slows down the reaction speed

Conventional refining agents that slow down the reaction rate generally use TiO 2 And cryolite, for general aluminum alloys, can achieve effective purification effect, but for alloys with higher purity requirements, it will pollute the alloy, and the refining process will produce a lot of smoke and dust to pollute the environment

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