多孔复合结合剂立方氮化硼砂轮磨损特性

Wear Behavior of Porous Composite-bonded CBN Abrasive Wheels

针对难加工材料高效磨削砂轮难以满足高气孔率与高强度要求问题,基于氧化铝空心陶瓷球颗粒造孔与增强,开发了一种新型多孔复合结合剂立方氮化硼(Cubic boron nitride,CBN)砂轮。开展了镍基高温合金磨削试验,分别从磨削力、砂轮径向磨损量、磨损形貌过程等方面分析多孔砂轮的磨损特性,并与白刚玉砂轮进行对比。研究表明:多孔复合结合剂CBN砂轮磨削高温合金的磨削力和磨削温度均小于白刚玉砂轮;当单位材料去除率为4 mm3/(mm·s)时,多孔复合结合剂CBN砂轮的磨削比是白刚玉砂轮的6倍;多孔复合结合剂CBN砂轮磨削高温合金的磨损形式主要是磨粒磨耗磨损、磨粒及结合剂破碎磨损及黏附磨损,磨损过程伴随新磨粒与气孔的出露。相比之下,白刚玉砂轮黏附堵塞现象严重,砂轮磨损快,工件表面质量难以保证。

In order to meet the wheel requirement of high porosity and high strength for the high efficiency grinding process of difficult-to-cut materials, a new type of porous composite-bonded cubic boron nitride （CBN） abrasive wheel is developed based on alumina bubble particles as pore-forming agent. The grinding experiments are conducted on nickel-based alloy respectively with the developed porous CBN wheel and white corundum grinding wheel. The grinding forces, radial wear and wheel wear forms are measured and investigated. Results show that, the grinding forces and grinding temperatures of porous CBN wheel are smaller than that of white corundum grinding wheel, and the grinding ratio is about 6 times higher when the material remove rate is 4 mlTl3/（/n.nl＇s）. The primary wear forms of porous composite-boned CBN wheel include abrasive abrasion wear, abrasive and bond fracture, and adhesion wear. Accompanied by the wear, new abrasives and pores are exposed. Serious wheel adhesion and loading phenomena are found during grinding with white corundum grinding wheel, and the radial wear of the corundum grinding wheel is almost 6 times that of porous one.