Basic Research On Microwave Sintering Of Metal Bonded Diamond Grinding Tool Segments

The heating method of microwave sintering is from inside to outside uniformly,which can not only avoid the temperature gradient inside the material caused by traditional heating process,but also can improve the heating rate and reduce the final sintering temperature effectively.At present,the application of microwave sintering is mainly concentrated in the fields of ceramics and powder metallurgy,and is relatively rare in the research of preparation of metal bonded diamond abrasive tools,sintering mechanism and the influence of sintering process parameters on wheels.Thus,the research on the preparation of metal bonded super-hard abrasive tools by microwave sintering is mainly focused on the following points:(1)Copper powder,iron powder,tin powder and nickel powder are chosen for copper based bond,MBD4 diamond for abrasive and different mass fraction of pore forming agent are added to generate pores.The metal/diamond composites of diamond abrasive segments are prepared by powder prepressing molding and microwave sintering in argon atmosphere.By contrast,the traditional atmosphere resistance furnace sintering are also used to prepare the metal/diamond composites of super-hard abrasive segments.(2)After the measurement on the porosity of sample,the change law of porosity effected by the content of pore forming agent,sintering temperature and molding pressure ware analyzed during this paper;The morphology,distribution and size of the pore inside the segments ware observed by scanning electron microscope(SEM).(3)The effect of pore forming agent,sintering temperature and molding pressure on the properties of segments such as bending strength,hardness and porosity has been tested by the hardness tester and three point bending strength test.(4)The diamond abrasive and the matrix bonding interface ware observed by scanning electron microscope(SEM),meanwhile,the elements on the surface of diamond abrasives was analyzed through the energy spectrum.(5)The alloying extent of the matrix which is influenced by sintering temperature was detected by means of XRD diffraction.(6)A set of constant pressure grinding device in linear motion with related fixtue ware designed for the grinding test of the tungsten carbide by using metal/diamond composites of diamond abrasive segments.The influence of the content of pore forming agent and sintering temperature on the surface quality of the workpiece and the grinding ratio of the matrix were mainly focused.