The Study On Infrared Thermal Wave Detection Thchnology For Inner Defects In Casting Product

The non-destructive infrared thermal wave technique is a rapidly developing method for non-destructive testing because it is a direct viewing,real-time,mobile,tele and large-area testing.It transfers the infrared thermal wave of the object to visible thermograph according to the relationship among infrared radiation,surface temperature and material properties.It can be inferred that whether there exists defects within the material via thermograph analysis.The non-destructive infrared thermal wave technique is now mainly utilized to detect defects on the surface and subsurface of material.For infrared thermal wave nondestructive testing,calibration using most of the existing quantitative manner,but because of the seized samples and the diversity of defects,there are certain limitations to identified is possible Thus,it requires to provide the basis for the selection of suitable infrared thermal imaging system and the development of accurate and reliable testing standards by use of theoretical models or numerical model tesing to determine the optimum parameters.In this article,it uses finite element analysis software COMSOL to simulate infrared thermal wave NDT process in order to improve the exsiting problems for the current infrared thermal wave thchnique.It analyzes the factors affecting infrared thermal wave testing and several different types of defects are given by the finite element simulation methods,and to provide basis for the structures of infrared thermal wave detection system.Finally,using the SAT-HY6601 infrared thermal image system for experimental verification.Combined with the characteristics of infrared images,the Retinex single image infrared thermal wave defect technique which is based on the global fields characteristics and infrared thermal wave sequence technique which is based on singular value decomposition(SVD) was discussed. The numerical simulation results and experimental results shows that the use of finite element of infrared thermal wave NDT for simulation analysis is feasible,and it is showed that the treated image accord with the requirements of defect detection.