Preparation method of 7XXX series aluminum alloy bar based on mechanical ultrasonic vibration aging

Abstract

The invention discloses a preparation method of a 7XXX series aluminum alloy bar based on mechanical ultrasonic vibration aging. The preparation method comprises the following steps that A, a 7XXX series aluminum alloy cast ingot is subjected to homogenization treatment; B, hot extrusion is conducted on the homogenized cast ingot to form the bar; and C, the bar obtained after hot extrusion is rotated to pass through a mechanical ultrasonic vibration device located at the fixed position, and the 7XXX series aluminum alloy bar based on mechanical ultrasonic vibration aging is obtained. According to the preparation method, the mechanical ultrasonic vibration aging device with four symmetrically distributed pressure heads is used for machining the hot extrusion bar, so that uniform precipitation of a nanoscale precipitated phase in an alloy, nanocrystallization of surface layer grains and gradient distribution of grain sizes are promoted, meanwhile, good surface quality and uniformity are achieved, the toughness and fatigue resistance of the 7XXX series aluminum alloy are remarkably improved, and combination of ultrahigh strength and good plasticity is achieved.

Description

technical field

[0001] The invention relates to the technical field of aluminum alloy processing, in particular to a method for preparing 7XXX series aluminum alloy rods based on mechanical ultrasonic vibration aging. Background technique

[0002] Because 7XXX series aluminum alloy has a series of advantages such as high strength, low density, good processing performance and resistance to stress corrosion cracking, it is often processed into various types of materials and widely used in rail transportation, aerospace, national defense and military fields. The 7XXX series aluminum alloys (mainly Al-Zn-Mg and Al-Zn-Mg-Cu two main alloy series) are typical precipitation-strengthened aluminum alloys, which are precipitated at the nanometer or submicron level in the alloy by controlling the effective aging process. Metastable precipitates such as Mg-Zn or Al-Mg-Zn can significantly increase the strength of the alloy and obtain ultra-high-strength aluminum alloys.

[0003] The co...

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