表面结构对内冷却砂轮磨削性能的影响

Effect of Surface Structure on Grinding Performance of Internal Cooling Grinding Wheel

针对高温合金磨削加工过程中存在磨削温度高、加工效率低等问题,设计了一种带有可更换磨料环的内冷却砂轮。为进一步提升磨削液在磨削弧区的流动特性和换热性能,基于葵花籽叶序排布模型,设计了磨料环的表面结构和内流道出口形状,基于计算流体动力学方法,建立了磨削弧区流场有限元模型,模拟了不同流道出口形状对内冷却砂轮磨削弧区流场分布的影响。开展了镍基高温合金GH4169的磨削试验研究。结果表明,磨粒族叶序排布方式有效增强了磨削液在磨削弧区的流动换热能力,相比圆形出口流道,矩形出口流道的冷却润滑效果更好,随着砂轮转速的增大其换热效率提升更显著,得到的磨削温度和工件表面粗糙度值分别平均降低24.12%和18.50%,已加工表面形貌更加平整、细腻。

Aiming at the overheating and low machining efficiency problems in grinding superalloys, an internal cooling grinding wheel with a replaceable abrasive ring is proposed. To improve the flow characteristic and heat transfer performance of fluid in the grinding arc zone, surface structure of the ring and the internal flow channel outlet shape are designed based on the sunflower seed phyllotaxis configuration model. The flow field distribution model in grinding arc zone is established based on the computational fluid dynamics(CFD) method, finally the grinding tests of superalloy are carried out. Results indicate that abrasive cluster of phyllotaxis configuration leads to enhanced flow and cooling characteristics, compared with the circular flow channel, better cooling and lubrication effects are obtained by the rectangular flow channel, and the heat exchange efficiency is more remarkable as the grinding speed increases. Average grinding temperature and surface roughness of the workpiece are reduced by 24.12% and 18.50% respectively, and the machined surface morphology is smoother and more regular.