精密铸件射线CR检测工艺参数对图像质量的影响

Influence of Process Parameters on Image Quality of Computed Radiography on Precision Castings

以含人工裂纹缺陷的精密铸造平板试件为检测对象,研究并分析了管电压、曝光量、焦距等工艺参数对射线CR图像质量的影响规律。结果表明:图像对比灵敏度和空间分辨率随管电压升高均呈先升高后降低趋势,随曝光量和焦距增加均呈先增加后稳定趋势;图像平均灰度随管电压升高和曝光量增加均呈降低趋势,随焦距增加没有明显变化;可识别最小裂纹缺陷尺寸随管电压升高呈先减小后增大的趋势,随曝光量和焦距增加呈先减小后稳定趋势。该研究结果可为精密铸件射线CR检测工程应用提供理论依据和数据支撑。

In this paper,taking the precision casting plate specimen with artificial crack defectsas the test object,the influences of process parameters such as tube voltage,exposure dose,focal distance on the computed radiography image quality were studied and analyzed.The results showed that the contrast sensitivity and spatial resolution of images first increased and then decreased with the increasing of tube voltage,and first increased and then stabilized with the increasing of exposure dose and focal distance;the average gray values of images decreased with the increasing of tube voltage and exposure dose,and did not change obviously with the increasing of focal distance;the minimum size of recognizable cracks first decreased and then increased with the increasing of tube voltage,and first decreased and then stabilized with the increasing of exposure dose and focal distance.These results will provide theoretical basis and data support for the engineering application of computed radiography detection to precision castings.