基于分形理论及数理统计的压铸件内部孔洞缺陷定量分析

对分布不规则的压铸件内部孔洞采用分形理论与数理统计的原理进行了分析.根据铸件切面的孔洞金相照片,采用计算机图像处理方法得到了反映孔洞缺陷分布均匀性的分形维数、孔洞面积的百分比、孔洞半径分布方差、孔洞的平均半径4个定量的参量.利用这4个定量参数可以综合的反映铸件内孔洞位置的分布状态和孔洞大小及分布状态.通过不同压铸工艺镁合金铸件内部气孔的分析,对计算和分析结果进行了验证.

Analysis of Cavity Defects of Die Castings by Fractal Theory and Statistic Method

The irregularity of cavity defects of die castings is quantitatively analyzed by fractal theory and statistic method. Characteristic parameters of cavity defects, such as fractal index, area ratio, average size and root square deviation of cavity radius are obtained to describe the uniformization of the cavity defects based on metallography and digital image analysis technology. By analyzing the four digital parameters, the radius and position state of cavity defect is found. The result is validated by analyzing porosities of magnesium alloy die casting of different processes. And based on this method which process of die casting is better can be gotten by comparing processes.