Design And Development On Monitoring Device Of Temperature Field In Laser Molten Pool

As a key technology in laser manufacturing, temperature field monitor technology of laser molten pool has been widely researched in home and abroad. And quantities of works are researched by many scholars. The monitoring of the temperature field of laser molten pool for real-time is very important for improving the part quality of laser manufacturing such as laser welding, laser cladding and direct fabrication metal part of laser rapid prototyping. Therefore, the research of temperature field has important academic value and has be meaningful in application.Based on the way of non-contact measurement, monitoring device of temperature field of laser molten pool is developed; a Two Charge Coupled Device colorimetric temperature measurement system is presented. In this system, two-CCD is used to capture two different wavelengths infrared images of the temperature field of laser molten pool. Two-CCD sends the images to the personal computer for processing them. The grey of two different wavelengths images are gotten to calculate the temperature of objective by using the principle of colorimetric temperature measurement. The effectiveness of monitoring system is validated by monitoring experiments of temperature field of laser molten pool. The experiments demonstrate that the system has quick response and a little influence of the environment, which can achieve the validate monitoring of temperature field. It provides a useful way for temperature measurement.Relevant temperature measurement software is developed according to the two-CCD colorimetric temperature measurement system. The software interface is very visible and the operation very easy. Temperature field of molten pool can be monitored and analyzed by real-time. The dynamic laser molten pool image can be shown by the software. Based on the image processing technology and colorimetric temperature measurement way, this software can show the appointed temperature value of laser molten pool for real-time. The real-time of software is verified by monitoring experiments of temperature field of laser molten pool.Analyzing the factors which influence two-CCD colorimetric temperature measurement system,the selection way of filters is pointed out. Filters are selected through monitoring experiments of temperature field of laser molten pool. The temperature measurement system of laser molten pool is calibrated by infrared temperature measurement detector. The sample of 45# steel is used for temperature measurement of molten pool, and error range of system is pointed out. Through monitoring experiments of the laser molten pool by the appointed sample, in the end, the experiment results validate the temperature measurement system and the real-time of temperature measurement software.