Semi-solid rheological squeeze casting forming method of flame retardant magnesium alloy

Abstract

The invention discloses a semi-solid rheological squeeze casting forming method of flame retardant magnesium alloy. The method includes the steps of the early processes of conventional melting, refining and slagging-off and two subsequent technological processes of semi-solid slurry preparation and semi-solid rheological squeeze casting; the semi-solid slurry preparation is achieved through imposing air bubble to flame retardant magnesium alloy melt to be stirred, and then squeeze casting forming is conducted on the obtained semi-solid slurry. Through the method, the semi-solid rheological squeeze casting forming of the flame retardant magnesium alloy is achieved, a primary phase and a secondary phase in the flame retardant magnesium alloy can be refined respectively, the casting overall organization is dense, the casting surface is high in quality, and the mechanical property and the surface quality of a product are greatly improved; the pouring temperature is decreased from 700 DEG C in a traditional process to about 600 DEG C, energy consumption can be lowered, impact to a mould is decreased, oxidation losses of magnesium alloy materials are lowered, and the utilization rate of the materials is improved.

Description

technical field [0001] The invention belongs to the technical field of semi-solid forming of metal materials, and in particular relates to a semi-solid rheological extrusion casting forming method of a flame-retardant magnesium alloy. Background technique [0002] Flame-retardant magnesium alloy is a hot spot in the field of magnesium alloy research. By adding a certain amount of flame-retardant alloy elements to magnesium alloy, it can inhibit the severe oxidation and combustion of magnesium alloy, and realize direct smelting and processing under atmospheric conditions. At present, the commonly used flame retardant alloying elements in magnesium alloy research include Ca, Be and rare earth elements. Ca is a commonly used alloying element in magnesium alloys. The research results on the flame retardant effect of Mg-Ca binary alloys show that the ignition point of magnesium alloys containing 1wt% Ca can be increased by 250 ° C; The oxide film is thin and the surface is smoot...

AI Technical Summary

Problems solved by technology

These processes mainly have two deficiencies: one is that when pouring at high temperature, the crystal grains are coarse, and a coarse network second phase is formed at the grain boundary, which seriously affects the mechanical properties of the alloy; the other is that after adding Ca element, the viscosity of the magnesium alloy melt increases. Large, difficult to fill, difficult to obtain parts with complete shape

Therefore, the use of semi-solid rheo-squeeze casting to prepare Ca-containing flame-retardant magnesium alloys has a good application prospect, but there is no semi-solid rheo-squeeze casting method suitable for flame-retardant magnesium alloys.

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