铝合金热分析冷却曲线特征值提取的数据处理方法

Data Processing Method of Characteristic Value Extraction From Thermal Analysis Cooling Curve of Aluminum Alloy

通过对微分热分析法在铝合金铸造生产上应用的研究,提出了一种从冷却曲线快速、准确提取特征值的数据处理方法,并在Matlab平台上编程。首先使用低通滤波、中值滤波、算术平均滤波的组合滤波方法去除温度数据中的干扰信号,然后采用一阶中心差商法求取微分曲线,并使用中值滤波、算术平均滤波对微分曲线进行平滑处理,最后通过冷却曲线和微分曲线之间的对应关系,提取出冷却曲线上的特征值。计算结果表明,该方法可行,求取的特征值比较准确。

Based on the application of differential thermal analysis method in aluminum alloy casting production, a data processing method, which is a fast and accurate method to extract characteristic values from cooling curve, was proposed using Matlab to write the program. Firstly, the low pass filter, median filter and arithmetic average filter were used to remove the interference signal in the temperature data. Then the differential curve was obtained by using the first order central difference quotient, and the differential curve was smoothed by median filter and arithmetic mean filter. Finally, the characteristic values of cooling curves were extracted by using the corresponding relationship between the cooling curve and the differential curve. From the results of the calculation, it can be known that the method is feasible and the characteristic values are accurate.