Effect of Flow Channel Structure on Performance of Pressurized Internal-cooling Slotted Grinding Wheels

Abstract

：Aiming at the overheating problem caused by the gas barrier effect of the grinding wheel in the grinding of nickel-base superalloys, a pressurized internal cooling grinding method is proposed. In view of the influence of the flow channel structure on the flow characteristics of the grinding fluid and the performance of the grinding wheel, and considering the processing technology of the flow channel and the centrifugal force caused by the rotation of the grinding wheel, two types of straight and curved internal channel structures are designed. The computational fluid dynamics method is used to analyze the influence of the channel structure on the flow field in the grinding zone. Results show that the fluid velocity and distribution uniformity of the grinding zone under the curved flow channel structure are higher. Two pressurized internal cooling slotted grinding wheels with curved and straight internal flow channels are prepared. The grinding comparison tests of nickel-base superalloy are carried out under the same grinding parameters, and the effects of grinding wheel speed and fluid pressure on the grinding temperature, surface roughness and morphology are analyzed. Results indicate that compared with the straight flow channel, better cooling and lubrication effects are obtained by the curved flow channel, and the heat exchange efficiency is more remarkable as the grinding speed and the fluid pressure increase. Grinding temperature and surface roughness of the workpiece are reduced by 16.8% and 17.6%, respectively, and a more regular surface morphology is obtained. Key words：flow channel structure；pressurized internal cooling；slotted grinding wheel；grinding performance；superalloy * 国家自然科学基金(51475404)、湖南省自然科学基金(2018JJ4082)、湖 南省教育厅重点(18A077)和湖南省普通高校青年骨干教师培养经费 (20151053008gg)资助项目。20180801 收到初稿，20181216 收到修改稿