对铝合金钨极氩弧焊搭接焊缝进行了X射线DR（数字射线）成像检测，得到了典型焊接缺陷的数字射线参考图像，定性分析了焊缝缺陷的图像特征。对典型缺陷的出现频数进行了统计分析，结果表明，手工钨极氩弧焊搭接焊缝的裂纹、气孔与夹杂缺陷的出现几率较高。对单个气孔、夹杂缺陷进行了分类。通过拉普拉斯锐化、浮雕特效和多尺度对比度增强方法对含裂纹的DR图像进行了缺陷增强显示，提高了人眼视觉效果。

X-ray DR (digital radiography) imaging is used to detect the lap joint of gas tungsten arc welding for aluminum alloy, the digital reference images of typical welding defects are obtained, and the characteristics of welding defect images are qualitatively analyzed. The statistical analysis of the occurrence frequency of the typical defects was performed and the results showed that the occurrence of cracks, pores and inclusions in TIG welding was high. The defect grades of individual pore or inclusion defect are classified. The crack defects of DR image are enhanced by Laplace sharpening, emboss effect and multi-scale contrast enhancement method, which improved the human visual effect.