夹层共底贮箱体积庞大，采用脉冲红外无损检测技术单次只能检测一小片区域，需要数百次检测才能完成对夹层共底贮箱的检测，单个工程不利于缺陷位置的判断。本文采用固定重叠区域的红外图像拼接方法，重叠区域采用加权融合方式可有效消除拼缝，夹层共底结构侧边 6个子区域采用弧形拼接方式，可有效解决弧形区域的拼接，可有效解决多工程拼接难题。采集工程缺陷标注后，拼接图像直接显示缺陷的位置信息，对于夹层共底结构缺陷信息判断带来了极大的便利。

锂电池端盖作为保障锂电池安全的关键部件，端盖是一种铝制的薄片，采用激光焊接工艺，焊接过程中容易造成焊穿孔、断焊、虚焊的现象，目前主要依靠目视检测、可见光图像检测，但上述检测方式不能检测出虚焊问题。本文使用脉冲红外热成像技术对激光焊接进行检测，制作了焊接率为 100%、50%、33%、25%共 4个试件，采用信号重建方法可以消除试件表面不匀的影响，一阶导图像可以看到焊接区域，焊接率越大，焊接区域亮斑越大；对图像进行二值分割，结果表明激光焊接率和检测面积成正相关线性关系，验证了脉冲红外热成像技术对锂电池端盖焊接质量检测的有效性，为锂电池端盖焊接质量检测提供了一种新方法。

Aiming at the drawbacks of low contrast and high noise in the thermal images, a novel method based on the combination of the thermal image sequence reconstruction and the first-order differential processing is proposed in this work, which is comprised of the following procedures. Firstly, the specimen with four fabricated defects with different sizes is detected by using pulsed infrared thermography. Then, a piecewise fitting based method is proposed to reconstruct the thermal image sequence to compress the data and remove the temporal noise of each pixel in the thermal image. Finally, the first-order differential processing based method is proposed to enhance the contrast. An experimental investigation into the specimen containing de-bond defects between the steel and the heat insulation layer is carried out to validate the effectiveness of the proposed method via the above procedures. The obtained results show that the proposed method can remove the noise, enhance the contrast, and even compress the data reaching at 99.1%, thus improving the detectability of pulsed infrared thermography on metal defects.