Metal Surface Defect Detection System Based on Semiconductor Laser and Infrared Thermal Imaging

摘要

A surface defect of a workpiece gives possibly rise to quality reduction and lower lifetime of a production. So, metal surface defect detection is a important part in industrial manufacture. The paper presents a kind of new metal surface defect detection system based on semiconductor laser and infrared thermal imaging. The system provides heat source through semiconductor laser and heats the surface of a workpiece through optical path expanding method. The defects on the workpiece will affect the diffusion of heat waves and cause changes in the temperature field of the material surface. The system can obtain data of surface temperature of a workpiece by use of infrared camera. A metal surface defect can be recognized and calculated by detection method of boundary temperature of defect on the workpiece. The experimental results show that the system is feasible and effective.