金属结合剂金刚石砂轮的修整研究(Ⅰ)——用立体照片对测量磨粒的突出高度及磨粒突出高度对磨削性能的影响

金属结合剂金刚石砂轮的磨粒突出高度极大地影响砂轮的磨削性能。磨粒突出高度大小容易导致砂轮堵塞从而使磨削力增大;磨粒突出高度太大则容易导致磨粒脱落从而使砂轮磨损加快。然而,迄今为止,精确测量磨粒突出高度的方法尚未见诸报道。本文提出了一种用立体照片对测量磨粒突出高度的方法,即所谓“3D法”,并对磨削Si_3N_4时,磨粒突出高度对砂轮磨削性能的影响进行了实验研究。砂轮的修整用杯形砂轮修整器完成。主要结论如下:(1)砂轮表面修整后,磨粒突出于金属结合剂基面,并且在磨粒后方存在一三角洲状结合剂残留物。磨粒突出高度分布近似为正态分布。(2)磨削力随磨削次数单调增加。(3)通过研究磨削力、工件表面粗糙度及砂轮磨损同磨粒突出高度的关系,对最佳磨粒突出高度进行了一些讨论。

Studies on Truing and Dressing of Diamond Wheels --Measurement of Protrusion Height of Abrasive Grains by Means of Stereo Pair and Influence of the Protrusion Height on Grinding Performance

The protrusion height of abrasive grains in a metal bonded diamond wheel plays animportant role in grinding performance. For example, the protrusion height too small causes loadingeasily and an increase of grinding force markedly, but the too large one causes attritious wear and re-leasing of cutting edges frequently. However the precise measuring method adapted to the protrusionheight has not been reported. In this paper, a new 3--dimensional measuring technique 3 D method]is developed by using SEM stereo pairs. And then the effect of the protrusion height in a diamondwheel trued and dressed with a GC cup--truer is investigated experimentally on grinding performanceof Si_3N_4 ceramics. The main results obtained are as follows: (1 ) After truing and dressing, abrasivegrains protrude above the flat base of metal bond and are followed with bond tails, the protrusionheight approximates to a normal distribution. (2)Grinding force grows monotonously with an increaseof grinding passes. (3)The optimum protrusion height is discussed by means of variations of grindingforce, finished surface roughness and wheel wear with an increase of primary protrusion height.