Method for measuring aluminum alloy continuous cooling transformation curve

Abstract

The invention relates to a method for measuring an aluminum alloy continuous cooling transformation curve, and belongs to the technical field of non-ferrous metal material preparation. According to the method provided by the invention, by recording the change of thermal equivalents in different temperature intervals, precipitation temperature intervals of quenching reaction in a quenching process are distinguished based on the change of the thermal equivalents. The method provided by the invention measures exothermic reaction of aluminum alloy in the quenching process by applying a differential scanning calorimetry (DSC), and combines with microstructure analysis and mechanical property testing, so as to obtain the aluminum alloy continuous cooling transformation curve. Compared with other methods, the method provided by the invention can distinguish initial and final temperatures of different quenching-induced precipitated phases based on accurate cooling curves in certain cooling intervals. The continuous cooling transformation curve obtained by the method provided 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...

AI Technical Summary

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 the continuous cooling transformation of some aluminum alloys is to detect the change process of the aluminum alloy quenching precipitates by studying the electrical conductivity (Electrical Conductivity) or electrical resistance (Electrical Resistivity) of the aluminum alloy during the continuous cooling process, but this method only Can measure the onset and end of the overall reaction and cannot distinguish between different cooling-induced phases during quenching

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.

Images