A method for measuring the continuous cooling transformation curve of aluminum alloy

Abstract

The invention relates to a method for measuring the continuous cooling transition curve of an aluminum alloy, belonging to the technical field of nonferrous metal material preparation. The present invention distinguishes the precipitation temperature interval of the quenching reaction in the quenching process according to the change of the heat equivalent by recording the change of the heat equivalent in different temperature intervals; the present invention measures the aluminum alloy by applying the differential scanning calorimetry (DSC) The exothermic reaction during the quenching process is combined with the microstructure analysis and mechanical property testing to obtain the continuous cooling transformation curve of the aluminum alloy. Compared with other methods, the method of the present invention is capable of obtaining precise cooling curves in a certain cooling interval and distinguishing the starting and ending temperatures of different quenching-induced precipitation phases. The continuous cooling transition curve obtained by the invention has the advantages of high precision, great guiding significance and the like.

Description

technical field [0001] The invention relates to a method for measuring the continuous cooling transition curve of an aluminum alloy, belonging to the technical field of nonferrous metal material preparation. Background technique [0002] It is generally believed that after solid solution heat treatment of aluminum alloy, the higher the quenching cooling rate, the better, because rapid quenching can fully maintain the supersaturated solid solution state of the alloy, so that the alloy has enough solid solution atoms during the aging precipitation process. However, there are serious quenching internal stresses in the rapidly cooled components. In the subsequent processing and application process, if the internal stress cannot be eliminated, the components will fail. Studies have shown that the precipitation of aluminum alloys in the quenching process follows certain kinetic and thermodynamic laws. By studying the continuous cooling transition curve in the quenching process, th...

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Problems solved by technology

[0004] 1. Compared with the continuous cooling transformation of steel, the continuous transformation speed of aluminum alloy is fast, which is difficult to be directly detected and analyzed;

[0005] 2. The quenching research of aluminum alloy lacks effective controllable quenching methods and equipment. Generally, specific quenching media are used to obtain different cooling curves to study the performance changes after quenching-aging. Commonly used quenching media include water, warm water, oil and some high Boiling point organic solvents

However, these research methods can only provide limited discontinuous cooling paths, even if some special cooling methods, such as Jominy end quenching experiments, can only provide nonlinear cooling paths in a certain cooling range

[0006] 3. The only research on continuous cooling transformation of some aluminum alloys is to detect the change process of aluminum alloy quenching precipitates by studying the electrical conductivity (Electrical Conductivity) or electrical resistance (Electrical Resistivity) of aluminum alloys during continuous cooling, but this The method can only measure the beginning and end of the overall reaction and cannot distinguish the difference between the different cooling-induced phases during the quenching process

But so far, there is no continuous cooling transition curve that can distinguish the difference between the different cooling-induced phases during the quenching process.

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