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缓进给磨削工艺适合于成型磨削,尤其在复杂型面构件的高效精密磨削中具有广阔应用前景。本文采用钎焊CBN砂轮进行了镍基铸造高温合金K424的缓磨试验,重点研究了工艺参数(砂轮线速度、工件进给速度、切深)对磨削加工性与表面完整性的影响,包括磨削力与磨削温度、磨削比能、尺寸稳定性、加工表面形貌、亚表面层的显微硬度与金相组织变化、残余应力。结果显示,尽管K424合金的磨削比能高达200-300J/mm3,但在钎焊CBN砂轮缓进给磨削K424合金过程中,磨削温度仅约为100℃。采用砂轮线速度22.5m/s、工件进给速度0.1m/min,以及切深0.2mm的工艺参数加工出满足尺寸精度要求的直槽。磨削表面未发现磨削烧伤与显微裂纹,并且呈压应力状态。
Slow feed to the grinding process is suitable for forming grinding, especially in the complex profile of high-precision components grinding has broad application prospects. In this paper, the brazing CBN grinding wheel was used to carry out the buffing test of nickel-based superalloy K424. The effects of process parameters (grinding wheel linear velocity, workpiece feed rate and depth of cut) on the grinding processability and surface integrity were studied, including Grinding force and grinding temperature, grinding specific energy, dimensional stability, machined surface morphology, subsurface layer microhardness and microstructure change, residual stress. The results show that the grinding temperature of K424 alloy is only about 100 ℃ during the grinding process of K424 alloy with brazing CBN grinding wheel, although the grinding ratio of K424 alloy can reach as high as 200-300J / mm3. Adopting the linear speed of wheel, 22.5m / s, workpiece feed rate of 0.1m / min, and cutting depth of 0.2mm process parameters to meet the requirements of the dimensional accuracy of the straight slot. Grinding surface is not found grinding burns and micro-cracks, and was compressive state.