Based On The Ccd Laser Manufacturing Bath Temperature Detection Research

Laser remanufacturing technology has been widely concentrated in the world recent years, which has become a new branch of advanced manufacturing technology. At present, research on it mainly concentrates on equipment, processing parameter and material. In order to solve problems in its industry application, the basic theory and technology on it need to be studied further, such as interaction mechanism between high power laser beam and powder stream, measurement of powder stream feeding, special CAD/CAM software, measurement and control of temperature, size and precision, and so on.There is transmission of energy, momentum and mass in laser molten pool, which would induce some phenomenon, such as heat exchange, convection and mass exchange. Temperature distribution in laser molten pool would strongly affect the transmission, and then influence its metallurgy performance and surface quality. It is important to study it on theory and experiment, which would improve laser remanufacturing technology.In order to study it further, the principle of laser remanufacturing technology was discussed in this paper. Development status of temperature measurement on it in the world was summarized in detail. The method of CCD measurement was proposed. The research mainly includes:1) Based on thermal radiation theory and properties of reflecting and absorbing between metal material and laser, characteristics of thermal radiation in laser molten pool were analyzed. The thermal radiation in visible wavelength could be detected in order to analyse temperature. In order to establish and analyse mathematics model on CCD measurement, surface emissivity variety of common materials at different wavelength, temperature and surface status was analyzed.2) Structure design of the system was developed. Based on Plank radiation law and temperature measurement colorimetry principle, CCD measurement model and CCD measurement device were set up. Based on CCD spectrum quantum efficiency curve, analysis on its response, sensitivity and temperature measurement error was developed. Choice of thermal radiation wavelength for temperature colormetry was analyzed. 3) Function demand and feasibility of its special software were analysed. Data stream of thermal radiation image in temperature measurement was described. Based on digital image processing technology and modularization design method, special software for laser remanufacturing was developed, which was discussed in detail, such as data acquisition, input/output, image processing, temperature computing module and program design.4) Different blackbody structure, temperature control and performance evaluation were analysed in detail. Temperature calibration experiments were developed by high temperature standard blackbody of National Institute of Metrology P.R.China. Relation equation between blackbody temperature and two color gray ratio of thermal radiation image was set up.5) Experiments on laser quenching and laser cladding at moving state were developed. Temperature field distributions at different processing parameters were analyzed. Experiments on laser remanufacturing industry application were developed. It was shown the process of laser remanufacturing could be supervised by the CCD temperature measurement system in real time.