断续磨削加工聚晶金刚石的机理研究

分别采用超声振动冲击和脉冲激光加热技术对开槽金刚石砂轮断续磨削加工聚晶金刚石过程中的机械冲击和热冲击进行了模拟实验研究.研究结果表明,在断续磨削加工过程中,由于开槽砂轮和工件之间接触面积变化引起的磨削力周期性变化,有利于聚晶金刚石材料加工表面上的晶粒产生脆性微细破碎去除;由于开槽砂轮和工件之间接触面积变化引起的热冲击,有利于聚晶金刚石材料加工表面上的晶粒产生微细裂纹和疲劳破碎.实验结果表明,开槽金刚石砂轮磨块切入部分的磨粒以破碎损耗为主,磨块切出部分的磨粒以机械磨耗、氧化、石墨化损耗为主.

Investigation on the Mechanism of Discontinuous Grinding Polycrystalline Diamond with Slotted Diamond Wheels

The mechanical shock and thermal impact in the machining process of discontinuous grinding polycrystalline diamond with slotted diamond wheels were investigated systemically by the simulation experiments of ultrasonic vibration and pulse laser heating respectively. Experimental results show that the mechanical shock caused by the periodical changing of grinding force is propitious to the micro brittle break up of the diamond grains in the machining area of polycrystalline diamond material. The thermal impact caused by the periodical changing of grinding temperature is favorable for the diamond grains in the machining area of polycrystalline diamond material to occur thermal micro cracks and fatigue cracking. Experimental results show that the diamond grains in the front part of the grinding pieces are consumed basically by breakage, and the diamond grains in the retral part of the grinding pieces are consumed mainly by mechanical wear, oxidation, and changing to graphite.