成型面干磨削用旋转热管砂轮换热性能研究

Investigation on Heat Transfer Performance of Rotating Heat Pipe Grinding Wheel in Dry Profile Grinding

制约难加工材料成型磨削的主要问题是磨削烧伤。现有的冷却技术大多基于冷却液进行冷却,而鲜有学者从砂轮基体本身的换热潜能出发来解决磨削热的疏导问题。提出借鉴高效传热性能热管技术实现磨削弧区强化换热的构想,针对典型盘类零件型面特征,制作了轴向旋转热管砂轮,通过监测热管内部的温度分布,分析了不同转速、充液率以及热流密度条件下轴向旋转热管砂轮的等效换热系数。通过对比有、无热管两种砂轮在干磨削钛合金TC4成型面时热管内部温度、磨削弧区温度、工件表面质量及工件表层金相组织等,证实了热管在强化成型磨削过程换热的优势。最终,对比了在使用热管和冷却液两种冷却方式下,所产生的能源消耗和CO_(2)排放量,证实了旋转热管技术在难加工材料绿色制造中的发展潜力。

The key issue that restricts the development of profile grinding in difficult-to machine materials is usually the thermal damage. Most studies have focused on the cooling efficiency of the coolant;however only few have investigated the heat transfer potency of the grinding wheel matrix. A new cooling method that incorporates a rotating heat pipe(RHP) in the grinding wheel has been proposed. A rotating heat pipe grinding wheel(RHP-GW) is fabricated according to the characteristic of the typical profile surface. The heat transfer performance of the RHP-GW is analyzed for different factors as rotational speed, heat flux and filling ratio by monitoring the internal temperature distribution. Comparative dry grinding of Ti-6Al-4V between a normal grinding wheel(N-GW) and the RHP-GW, a great cooling advantage of the latter one is demonstrated. The workpiece surface quality and the grinding temperature in both the RHP and along the grinding zone are monitored. The energy consumption and CO2 emission is compared by both coolant cooling and RHP cooling, results show great potency on green machining of heat pipe technology.