Thermal analysis test method and apparatus of magnesium and magnesium alloy deteriorative processing tissue thinning effect

Abstract

The invention relates to a thermal analysis testing method of magnesium and magnesium alloy deteriorate process organizing thinning effect, which specifically uses the correlation between the deteriorate effect and the characteristic parameter on the cooling rate curve when a fused mass is solidified, establishes a thermal analysis testing technique, and develops a corresponding thermal analysis apparatus based on the thermal analysis testing technique. The thermal analysis testing technique of the invention has the following steps: 1, establishing a thermal analysis cooling curve (T -t); 2, derivation to the cooling curve to obtain a cooling rate curve (dT / dt -t); 3, respectively calculating the recalescence exothermic peak areas of the fused mass fore and after the deterioration; 4, defining the deterioration degree to judge the deterioration effect. The thermal analysis process includes data capture, computer analysis of the cooling curve, quantization of the exothermic peak areas, and result comparison; the process is realized by the computer and data analysis software, which are configured to a computer aided thermal analysis detecting device. The thermal analysis testing method and testing apparatus of the invention can be used in the smelting field of magnesium and magnesium alloy, as a ladle analysis approach to control and improve the metallurgy quality.

Description

technical field [0001] The invention relates to a method for analyzing and controlling the melt quality of magnesium and magnesium alloys during the smelting process, specifically a thermal analysis detection method and device for the microstructure refinement effect of magnesium and magnesium alloy modification treatment. Performance characteristics, realize the control of alloy structure and performance. Background technique [0002] As a new type of metal material, magnesium alloy has been widely used in aerospace, automobile, 3C (computer, communication, consumer electronics) and other fields due to its advantages of low density, high specific strength and specific stiffness. Take the automobile industry as an example: On the one hand, automobile exhaust emissions account for about 65% of global air pollution; on the other hand, problems such as energy shortage and rising oil prices are becoming more and more serious. Car weight reduction is an effective measure to solv...

AI Technical Summary

Problems solved by technology

Tch is the dendrite interference temperature, which can be accurately measured by the double thermocouple method. Theoretically, when the melt modification effect is good, the values ​​of Te and Tch should increase, but the increase is not large, and it is easy to be covered by equipment errors and human factors, and Ti , Te, Tch are temperature parameters, although the numerical accuracy is high, but it is greatly affected by the error of the thermocouple

ΔT is the apparent supercooling degree, that is, the difference between the supercooling temperature at the beginning of the solidification process and the maximum temperature of the reglow temperature. The study on the cooling curve of magnesium alloys found that under general solidification conditions, there is little reglow at the initial stage of solidification. , even if it occurs, the magnitude is very small, which is related to the small latent heat of solidification of magnesium: the latent heat of solidification of magnesium is 8.954kJ / mol, which is lower than that of aluminum (10.790kJ / mol) and iron (13.80kJ / mol), so The traditional parameter most widely used in grain refinement analysis of aluminum alloys—the apparent undercooling ΔT value is not applicable to magnesium alloys either.

Images