Study On Wettability Of PDC Tools Based On High Frequency Induction Brazing

Polycrystalline diamond composite?PDC?tools not only has the features of high hardness and good wear resistance as diamond,but also has the advantages of good strength and toughness as cemented carbide.PDC tools are widely used in cutting,drilling and other fields.Now PDC tools are almost made by brazing,and the wettability during welding is one of the key factors that affect the quality of brazing.It is an efficient way to produce PDC tools by hi-frequency induction brazing due to its characteristics of rapid heating and controllable temperature.Based on the process of high-frequency induction brazing of PDC and cemented carbide substrate in engineering practice,the wettability test was designed to provide experimental basis and theoretical guidance for PDC high-frequency induction brazing from the perspective of wettability.Firstly,strictly based on the PDC tool welding process,the wettability test was performed on the SP-15 high-frequency induction welding machine.Four kinds of brazing filler metal and four kinds of brazing flux were selected for the test.Welding parameters were selected as induction current and continuous heating time after the brazing filler metal was completely melted.Each parameter has four levels.Based on these factors,a four-factor four-level orthogonal test was designed.Then,the spreading area and spreading coefficient was measured by the VHX-600E 3D microscope with super wide depth of field.The wetting angle was measured by the neaSNOM Ultra-high resolution scattering near-field optical microscope.From spreading coefficient and wetting angle,the wettability was studied and researched.Finally,with the help of scanning electron microscope/energy spectrometer,the structural characterization and element diffusion of the sample were displayed.With the aid of X-ray diffractometer the phase composition of the test sample was shown.The results show that the Ag,Cu,and Zn elements in the sample solder diffuse into the cemented carbide matrix,and the W and Co elements in the matrix diffuse into the solder.The AgNiO₂ phase,AgCo?CO?₄ phase,CoZn₁₃3 phase,AgZn₃ phase,CuCo?CO?₄ phase was generated under brazing conditions of the14th group,which was confirmed as the best wettability.To sum up,on the selected cemented carbide substrate,using BAg50ZnCdCuNi solder,QJ102 flux,240A induction current,the heating time that last until the solder completely melted is the best test condition on the perspective of wettability.