Heat treatment process for improving dimensional stability of aluminium alloy motor shell

Abstract

The invention discloses a heat treatment process for improving the dimensional stability of an aluminium alloy motor shell, comprising the following steps: firstly, controlling on-line solution hardening for extrusion of sections of the aluminium alloy motor shell, introducing 2-3% of plastic strain and internal stress to the material through a secondary plastic forming process of an inner cavityof the shell, thereby forming a T3 state unstable under room temperature; then, performing precipitation heat treatment to the aluminium alloy motor shell after secondary plastic forming, obtaining astable alloy in a T7 state through overaging treatment, thereby improving the dimensional stability of the inner cavity of the shell after secondary plastic forming. The processing of two end surfaceholes by a numerical control processing procedure, tapping and inner diameter turning processing are performed to the aluminium alloy shell after overaging treatment, and then the internal stress is eliminated, and meanwhile, the additional heat treatment, namely desolvation, is performed for 1.5 hours at 190 DEG C, so that the mechanical processing precision of the shell can be maintained to have an expected size and the maximum using stability can be achieved.

Description

Technical field [0001] The invention relates to a method for manufacturing an aluminum alloy extruded motor housing, in particular to a heat treatment process method for improving the dimensional stability of the aluminum alloy motor housing. Background technique [0002] The motor shell obtained by the extrusion method is mostly medium-strength 6063 aluminum alloy, and the secondary plastic forming is realized by the hydraulic bulging device of the inner cavity of the extruded shell, and at the same time, the inner diameter and shape size formed in the extruded state are corrected. Deviation, including coaxiality, cylindricity, etc. Chinese Patent Application No. 201120224727.X, titled "Hydraulic Expanding Device for Secondary Plastic Forming of Motor Housing Cavity", discloses a hydraulic expanding device for secondary plastic forming of the motor housing cavity and using 6063 aluminum The processing method of the alloy motor casing extruded profile to make the motor casing. ...

AI Technical Summary

Problems solved by technology

Its disadvantage is that it ignores the residual stress caused by the formation of a temperature gradient from the inner wall to the surface when the extruded shell is quenched and rapidly cooled on-line as a thick-walled extruded profile, and the internal stress introduced by the expander during the secondary hydraulic plastic forming process. stresses; these residual stresses, together with further precipitation (precipitation) of the alloy material in the naturally aged state, are potential causes of dimensional changes in the inner diameter