Terahertz for Non-Destructive Quality Control of Laser Assisted Plastics-Metal Joints

Hybrid plastics-metal (PM) joints via direct non-contact laser assisted process without using any extra adhesive bonds or mechanical union is of great interest to many manufacturing sectors. However, quality control of the final product as well as at every production step needs to be developed for this new process. Therefore, we are looking for an effective and low-cost non-destructive testing method which can identify hybrid joining quality. Especially when traditional inspecting methods always have drawbacks, either they are destructive, offline, maybe harmful to inspector, and can increase the cost of products. In this paper, we present the ability of using Terahertz time-domain spectroscopy and imaging for non-destructive testing of laser welded PM joint samples. This study, conducted for the first time to the best of our knowledge, can potentially assist the manufacturing process and contribute to improve the quality of final PM welding products.