Fundmental Studies On Residual Stress Of High-temperature Brazed Diamond Grain

The researches on the stress field of high-temperature brazed diamond samples are very important, because they can make for adjusting brazing process to improve the machining capability. This paper suggests to studying the stress of brazed diamond's tools by the means of the finite element analysis (FEA). On the condition of reasonable premise and only concerned the mismatch of thermal and mechanical properties, the change of the thermal field and stress field is probed to analyze the residual stress of the brazed diamond in the brazing processes of vacuum resistance stove and hi-frequency induction heating apparatus by the means of the finite element analysis (FEA) modeling, respectively. Finally, the diamond residual stress is measured by the means of Raman.The main creative contents in the paper are as follows:1. Modeling of the brazed samples heated by vacuum resistance stove and hi-frequency induction has been conducted. And the results show that the difference of thermal expansion coefficient of the base, filler alloy and diamond result in large thermal stress, especially the area of filler alloy which near the diamond. Although the diamond's thermal expansion coefficient is smallest, which causes the thermal stress in the diamond grain but it is not big enough to cause diamond fracture. The simulation results in the hi-frequency induction are conformed but bigger than the simulation results in the vacuum resistance stove. It is shown that different welding arts and crafts affect the stress of diamond's alloy.2. The measuring experiments of the residual stress of the brazed diamond grains in vacuum resistance stove and hi-frequency induction by Raman has been finished and the results inosculate with the modeling ones well.3. By changing the brazing alloy and brazing alloy's climbing height, Modeling of the brazed samples has done. The results show different brazing alloys are connected with the stress of the brazed diamond samples. And when the climbing height is increased, the biggest stress is minished, but the stress field is increased. So, we should choose the brazing alloy and brazing alloy's climbing height reasonably by the practice.