金属结合层包覆单列磨粒小直径CBN砂轮端面磨削过程研究

金属结合层包覆单列磨粒小直径CBN砂轮在端面磨削过程中突出高度不同的CBN磨粒相继发生后面磨损、切削刃破碎和脱落，产生了砂轮自锐效应。砂轮磨削力呈现低频起伏和高频波动变化的特征，这是由于磨削过程中CBN磨粒后面磨损钝化使磨削力增大以及随后磨钝磨粒破碎变得锐利使磨削力减小的综合作用结果。砂轮磨削过程受到CBN磨粒性能及其切削刃状态的支配，多晶强韧CBN磨粒(BORAZON550，GE产品)耐磨性改善、磨粒微细破碎保持了砂轮的锐利性，延长了单个磨粒服务时间，突出高度不同的磨粒加入磨削过程的批次效应显著，磨削力低频起伏明显，单晶CBN磨粒(BORAZON500，GE产品)破碎范围大有效降低了磨粒切削刃突出高度、新磨粒加入磨削的过程具有连续性，磨削力高频波动明显。

STUDIES ON FACE GRINDING PROCESS OF METAL LAYER BOND WRAPPED MONORAIL GRIT CUP CBN QUILL

The grinding effects of small diameter cup CBN wheel which monorail grit is wrapped by metal layer bond (it is named monorail grit CBN quill) in face grinding of bottom of grooves are discussed. There is wheel self-dressing of monorail grit CBN quill in the grinding process. The flank wear, edge chipping, crack, breaking and fall off of CBN grits are happened in succession. The grinding force of monorail grit CBN quill changeful characteristics of low-frequent and high-frequent fluctuation, which is the integrated function of CBN grit being blunt during the flank wear and subsequently the blunt grits occurring chipping and breaking. The process is dominated by the performance of CBN grit and state of its cutting edge. High-toughness polycrystalline CBN grit (BORAZON550, GE type) will keep the sharpness of monorail grit CBN quill, prolong the serve time of single grit, has obvious group-effect when new grit with low protrusion height add to grinding process and grinding force has obvious low-frequent fluctuation. It will be processed continuously that single-crystal CBN grit (BORAZON500, GE type) is breaking and chipping and accordingly new grit cutting edges join to grinding process, as the results, grinding force will show high-frequent fluctuation obviously.