A pulse current assisted homogenization heat treatment method for aluminum alloy

Abstract

The invention discloses a pulse current assisted aluminum alloy homogenization heat treatment method. The method is characterized in that an alloy workpiece is connected with a current generation device, and the alloy workpiece undergoes heat insulation in a heat treatment furnace; a heat insulation temperature is a routine homogenization heat treatment temperature or is 5-15DEG C lower than the routine homogenization heat treatment temperature; a pulse current is applied to the alloy workpiece when a heat insulation time reaches 30-70% of a total routine alloy homogenization heat time; and after the treatment time of the alloy workpiece reaches the total routine homogenization time, power-off and discharge from the furnace are sequentially carried out. The method respectively considers the phases with different properties in the cast state of an aluminum alloy, and utilizes the Peltier heat effect and parts of joule heat of the interface of a current flowing substrate and an intermetallic compound after the solid solution of low melting point compounds in the cast is full in the homogenization heat treatment process in order to promote the elimination of a sharp interface between a high melting point phase and the aluminum alloy substrate.

Description

technical field [0001] The invention relates to a new technology for thermal processing of aluminum alloys, in particular to a process method for performing auxiliary homogenization heat treatment on aluminum alloy castings or ingots, and belongs to the field of metal alloy manufacturing processes. Background technique [0002] During the aluminum alloy casting process, according to the non-equilibrium solidification characteristics of the ingot, dendrite segregation or even macro segregation is easy to form in the ingot / casting, and alloy compounds are formed on the grain boundary, resulting in uneven structure and composition of the ingot. Greatly affects the performance of the ingot. Therefore, for ingots that need further pressure processing or some castings that need to be stressed, it is generally necessary to perform a homogenization annealing first to eliminate the segregation of various elements, so that the ingot / casting structure is uniform, and the pressure is el...

AI Technical Summary

Problems solved by technology

However, the general homogenization heat treatment process conditions can only eliminate some conventional low melting point alloy compounds, and it is difficult to eliminate the adverse effects of these high hardness, high melting point intermetallic compounds. If the homogenization heat treatment temperature and time are increased, on the one hand, The loss of energy consumption, on the other hand, it is easy to overheat or even burn in some areas of the ingot / casting, seriously affecting the overall performance