Study On Numerical Analysis And Measurement Of Temperature Field In Molten Pool For Laser Remanufacturing

As a research focus on laser processing and advanced manufacturing technique, laser remanufacturing technique has been investigated recent years. It has not been widely in a development stage and reached the desired result. At present, study on laser remanufacturing is concentrated on the development of equipments, technique and materials. The basic theory of laser remanufacturing need to be developed deeply, which limited the application of it, such as coupling theory of relation between high energy power laser beam and powder stream, measurement of powder stream, development of CAD/CAM of laser remanufacturing technique, temperature measurement and measurement control, and so on.The paper introduced the principle of laser remanufacturing and development of it in the world. Measurement of temperature field in laser molten pool by CCD was developed. The researches mainly included:1. The physical model and numerical model of laser molten pool were established. Temperature field distribution in laser molten pool at different time, different velocity of laser moving, different power, different thickness of physical model and different diameter of laser beam spot could be displayed by ANSYS numerical analysis method.2. Measurement method of temperature field by two color calibration was developed, based on Plank radiation law. Measurement model of temperature field in laser molten pool with two color calibration by CCD was established. Analysis of response, sensitivity and temperature measurement error was developed. When it was chose B(blue) and G(green) as the two color calibration, the temperature measurement system had good linear response, good sensitivity, and little temperature measurement error.3. Single tunnel color CCD method was chose by structure analysis of single tunnel and two tunnel temperature measurement systems. Structure and components and of temperature measurement system was developed. Refracting temperature measurement system by CCD was established. It was simple in structure and practical in laser remanufacturing process.4. Photos of laser molten pool were taken at conditions of side powder feedingand co-axial powder feeding. The color image distribution of laser molten pool was got by digital image processing.