Research On Measurement In High Energy Density Beam Welding Temperature Field

The quality of high energy density beam is related with the distribution of temperature field. So the Real-time examination and control of the welding temperature is the key to ensure the quality of welding and it has been one of the problem that is must be solved as early as possible.This thesis researches the temperature field measurement of the welding of electron beam in the vacuum and laser welding pool.Based on the environmental particularity of electron beam in the vacuum, a bran-new measurement system of temperature field has been studied and designed. Measurement principle of the real-time examining system of the welding temperature field with electron beam, the whole structure of the system and the design of software have been introduced combined with geometry optics, theories of radiation, CCD and tricolor measurement temperature. The idea of data modeling has been put forward after modeling temperature of blackbody and experimental data. The errors between the temperature computed and experimental data are small. Several important factors influencing the temperature examination and the way to reduce the errors have been analyzed.Temperature measurement with colorimetric method by CCD has been used to measure the temperature of the laser welding pool. In order to get the whole information of the wide range temperature field, three shut off time has been applied for different temperature range of the field. Data collecting and processing method of temperature in each temperature range as well as synthesizing the three temperature field into one has been described. Factors influencing wavelength and bandwidth have been analyzed. Choosing course has been discussed. The best range of wavelength and bandwidth has been confirmed after quantitative analysis aimed at given temperature range and simulating the influence of changes of wavelength and bandwidth on the ratio of gray.