合金化改善多孔砂轮磨削性能的研究

Effects of alloying additives on the grinding performance of porous wheels

通过对不含合金元素Co和添加3%Co的两种孔隙率高达38%的多孔金刚石砂轮进行磨削实验,测定它们在不同磨削条件下的磨削力,并观察磨削后砂轮的表面形貌,综合两砂轮的磨削力、力比Fz/Fx、比磨削能的大小、磨削一定体积材料后比磨削能的增量大小,以及磨削后两砂轮的表面形貌特征等实验结果,对两种砂轮的磨削性能进行分析评价.结果表明,在相同的磨削条件下,添加3%Co的砂轮Ⅱ的磨削力、力比Fz/Fx以及比磨削能均小于不含合金元素Co的砂轮Ⅰ,磨除同样体积的花岗石材料后两砂轮的比磨削能的增加量都不大,并且砂轮Ⅱ的比磨削能的增加量始终小于砂轮Ⅰ的比磨削能的增加量.两种砂轮磨削一定体积的花岗石后,在砂轮Ⅰ表面有较多的金刚石脱落坑,同时胎体出现较深的磨痕.

Two metal -bonded diamond wheels with high porosity of 38% were fabricated. One of the wheels contains 3% Co while the other one doesn＇ t. Grinding experiments with these two wheels on granite were carried out under different grinding conditions. Grinding forces were measured and the worn pattern of diamond wheels was observed. Evaluation on their grinding performances was based on the results of the grinding forces, the ratio of vertical grinding force and horizontal grinding force （Fx/Fx）, the specific energy , the increment of the specific energy after a certain amount of granite were grinded, as well as the topographies of the ground wheels. Experimental results revealed that the grinding forces, the ratio of Fx/Fx and the specific energy of wheel Ⅱ with 3% Co are smaller than that of wheel Ⅰ without Co. The increment of the specific energy after a certain amount of granite were grinded with these two wheels was small and the increment of the specific energy of wheel Ⅱ was even smaller than that of wheel Ⅰ .More pull - outs of diamond grits, and much more serious erosion on the metal bond on the surface of wheel Ⅰ was observed.