Research On The Bonding At Diamond/Matrix Interfaces Of Sintered And Brazed Tools And Their Performance In Vertical Grinding Of Stone

Diamond tools are not only widely applied in the traditional areas, such as construction, stone material manufacturing, automobile industry, transportation, geological survey and defense industries, but also used in the new areas of the jewelry, medical instrument, timber, glass fiber reinforced plastics, stone handicraft, ceramics and composite non-meta hard and brittle materials. The demand of diamond tool is largely increasing annually. Considering without increase of manufacturing cost, the studies that aim to improve the cutting performance and service life of the diamond tools is significant and necessary.Results show that the rare earth element has relatively strong redox capacity, which effectively improves the mechanical properties of cupper based diamond segment, and reinforces the control of matrix material on diamond. The addition of TiH2in the matrix can significantly improve the bending strength and hardness of the segment, and the influence of TiH2component on mechanical properties exceed that of the the rare earth element, indicating titanium element, whether if form of compound or as coating, can promote the bonding of diamond and matrixNi-Cr alloy shows good infiltration and holding on the diamond abrasive. In the process of the brazed diamond tool, the active element of Cr and C atoms react at the interface, and form the reaction layer, consequently the obvious diffusion happened at the interface and form the new stable bind structure of carbide, promoting the infiltration between each other, to enhance the control of diamond tool to certain extent.The forces with the sintered diamond tool are relatively large along the vertical and horizontal directions, and then are gradually prone to be stable in certain range. However, the forces with the brazed diamond tool gradually increase and exceed that of the sintering diamond tool. The protrusion height of the brazed diamond tool significantly decrease during its grinding process, and the height varies and stabilize, along with the grinding process; while for the sintered diamond tool, the protrusion height change little after multiple grindings and keep stable.Based on the microscopic experiments, this thesis discusses the product of interface between the diamond grit and matrix and its structure, state and formation environment, along with the influence mechanisms of these factors on the diamond bond strength. The results will shed light on the science and engineering practice of reducing unusual failure of the diamond grits and developing new diamond tool with high bond strength.