Research On PCD Tool's Temperature Field During Hi-frequency Induction Brazing

Polycrystalline diamond(PCD)tools are excellent tools in precisely manufacturing since its high hardness and high wear resistance.And it is an efficient way to produce PCD tools by hi-frequency induction brazing.The brazing temperature influences the thermal damage degree of the PCD tool and its shear strength,which is the key factor affecting the PCD tool's quality.Therefore,it is necessary to study on the temperature distribution and variation of the PCD tool brazing temperature.Firstly,it is vital to realize the magnetic-thermal bidirectional coupling process in brazing temperature calculation.The eddy current field and temperature field governing equations were derived based on Maxwell's equations and thermodynamic laws.Based on these governing equations,the brazing temperature field of the PCD tool can be calculated by COMSOL multi-physics software.Secondly,setting the cylindrical cutter bar as the induction heating object.And the finite element model of the high-frequency induction brazing temperature field of the 2D axisymmetric PCD tool according to above object is established to calculate its brazing temperature.According to sequentially changing the parameters of the coil number,coil radius and coil current of the model,the PCD tool's brazing temperatures of different conditions were calculated.And the temperature variation law of the tool brazing joint,the eddy current density and temperature distribution laws of the tool along the parallel direction of the magnetic force line were analyzed.Thirdly,setting indexable tool as induction heating object.The 3D nonlinear finite element model of PCD tool's hi-frequency induction brazing temperature field was established according to above heating object.According to the calculation,changing and distributed laws of PCD tool's three sections' temperature field were analyzed.And curves of three key transversal temperature gradient and temperature changes of the front and end tips were drawn.Based on the 3D model,the indexable PCD tool's hi-frequency induction temperature calculation software was developed by model-parameterizing.Lastly,the brazing temperature of the PCD tool were captured by infrared thermal camera,and it was used to prove the above FEMs' calculation results.The results showed that the temperature deviation between calculation and experiment turned greater when coil number was 1,while the deviation was lesser when coil number was more than 2.And when the brazing temperature reached the range of 620?~690?,the deviation between experiments and calculation fluctuated at 20?,there were good consistencies between experiments and calculation results.Since the verification was good,the appropriate parameters of brazing can be set based on the studied PCD tool's induction brazing temperature models.