Superhard Material Engineering 

Abstract: The paper introduces bit selection method while drilling with diamond bit through the so called skidding strata where the bit tends to shift away and the applied routine methods focusing on acid treatment method with its application cases and result.

Abstract: Diamond is an ultimate material in terms of hardness,thermal conductivity and chemical resistance,and widely used in the cutting tools,abrasives,thermal devices and optical windows.The application of pulsed or ultrashort pulsed lasers in micromachining of diamond materials can promote the utilization of diamond materials in various fields.In this paper,the advance of research on the mechanism of machining of diamond materials by pulsed laser was generalized.The pulsed laser induced diamond graphitization and laser ablation in the machining of diamond materials were summarized.

Abstract: There are many problems in manufacturing diamond tools,such as lack retention,grain shedding,oxidation and graphitization etc.,which affect the working life and efficiency of the tools.The surface coating metal of diamond is the effective method.Through discussing the condition of surface coated diamond,the coating theory and the metalizing model,the techniques and development of coated diamond are summed up,and some newest achievement in this field are introduced,and the possibility of practical application in production are analyzed.

Abstract: In the paper,polycrystalline diamond compacts(PDC)were synthesized under different sintering temperature and time by invariable pressure and their wear resistance were tested.After treatment at 750℃in air,wear resistance of these PDC were tested again.The results of the experiment show that the G-ratio increases first and then decreases with sintering temperature increasing.Similar results are obtained by different sintering time.The best technology in this experiment is to sinter 6 minutes at the temperature T3.The second sintering in air can improve wear resistance of insufficient sintering PDC.The experiment shown that under the pressure of 5~5.5GPa,temperature T3,sintering time 6minutes,perfect sample will be obtained,and the G-ratio can reach as high as 40×104.