Simulation Analysis Of Temperature Field Of Laser Brazing Diamond

High temperature brazing diamond tool has many advantages such as high abrasive grain and high cutting strength.Therefore,it is widely used in machining difficult to machine materials and precision machining.There are many methods for manufacturing diamond tools,each methods have their own advantages and disadvantages.Compared with the traditional brazing process,laser brazing diamond process can locally heat and affect the area smaller when it is used,which ensures that the matrix is not easy to deform during the brazing process.But the laser energy is strong and fast,and the thermal gradient is large,so it is easy to cause diamond to produce thermal damage(graphitization and fragmentation),and the solder layer cracks,leading to diamond falling.In this paper,45 steel as substrate,Ni-Cr solder to solder layer,diamond abrasive particle size is 35/40 mesh as the research object,the laser used for pulse laser(Nd:YAG laser),using the finite element software ANSYS simulation analysis and Discussion on laser brazing of diamond in the process of temperature field.The main research work and conclusion of this paper are summarized as follows:(1)The simulation model of fixed point heating brazing is established,and the model of heat source is the Gauss heat source.The temperature measuring method and instrument are selected to build a temperature measuring platform to verify the temperature measurement of the mathematical model of laser fixed-point brazing.The DO loop statements are written in APDL to realize the loading of the pulsed laser heat source.The initial parameter set is simulated and analyzed,and the trend of temperature with pulse load is obtained.(2)Based on the initial specification group of laser fixed point brazing,a single volume and two variables were changed to simulate the experiment.The effects of laser parameters: peak power,pulse width and frequency on the temperature field of laser fixed point heating brazing were obtained.(3)The simulation physical model of the scanning heating brazing is establishedand the simulation analysis is carried out.According to the simulation analysis results of laser fixed point brazing,the selected laser processing parameters,the peak power selection range is 1600W~1900W,the frequency selection range is 25HZ~40HZ,the pulse width is selected to 2.5ms~4ms,and the scanning speed is selected10mm/min~25mm/min.A reasonable orthogonal test is designed,with the maximum temperature and temperature fluctuation in steady state,and the time of melting of the filler metal can be used as an index parameter.Combined with the orthogonal test results,the influence of peak power,pulse width,frequency and scanning speed on the index parameters is quantified,and the influence trend and relationship of the four parameters on the three indicators are obtained.It is concluded that under the condition that the average power is constant,the frequency of the pulsed laser can be adjusted appropriately,and a small peak power and a larger pulse width can be selected.The appropriate scanning speed is between 15 and 25mm/min.(4)According to the brazing heating demand,the overall trend of simulation results after the change of parameters,the relationship between process parameters and three indicators.The suitable parameter group is selected to carry on the brazing experiment,and then the test analysis is carried out.The welding result is good.It shows that the selection of parameters by simulating the general trend of temperature by simulation is of great help to the process test.