摘要
采用多孔金属结合剂CBN砂轮,对镍基高温合金开展了缓进深切磨削相关理论与试验研究。基于实测磨削温度信号和圆弧接触移动热源模型,建立了深切磨削条件下磨削区内流体对流换热系数(Convection heat transfer coefficient,CHTC)分布的反推计算方法。在缓进深切模式下,磨削区内对流换热系数分布形态与传统浅磨明显不同。磨削区内的对流换热系数分布分为两段曲线,在磨削区前端的小区间,磨削液对流换热系数有一个明显的上升段,在主对流换热区,对流换热系数变化相对平缓。接触弧长和进给速度的变化对主对流换热区的对流换热系数分布影响较小,磨削速度是影响对流换热系数的主要因素。在磨削速度28~42 m/s范围内,宏观对流换热系数为23000~25000 W/m^(2)·K,磨削速度提高至50 m/s,对流换热系数有所降低,为16000~19000 W/m^(2)·K。该研究表明,采用多孔金属结合剂砂轮和油基磨削液,可在磨削弧长较大的条件下实现对磨削区的有效对流换热。
Theoretical and experimental study has been conducted under creep-feed grinding mode,using a porous metal bond CBN wheel and an oil-based grinding fluid,for the machining of a nickel based super alloy.An inverse heat transfer approach is proposed to derive the distribution of CHTC(convection heat transfer coefficient)in the grinding zone under deep grinding conditions,based on the measured grinding temperature signals and the circular-arc contact moving heat source model.Under creep-feed grinding mode,the CHTC distribution along the grinding zone presents a rather different pattern compared to that in the conventional shallow-cut grinding,at a small region of the front grinding zone,the CHTC shows a sharp rising curve,whilst in the main heat exchange area,the CHTC changes rather smoothly.The change of contact arc length and feed rate has little effect on the distribution of CHTC in the main heat exchange area,and the grinding speed is the main factor affecting the CHTC.As the grinding speed is in the range of 28-42 m/s,the global CHTC is about 23000 to 25000W/m^(2)·K,when the grinding speed increases to 50 m/s,the CHTC shows a modest decrease,down to about 16000 to 19000 W/m^(2)·K.Present study shows that,using a porous metal bond CBN wheel and oil-based grinding fluid,effective convective cooling can be achieved under large grinding contact arc lengths.
作者
金滩
马鑫
胡浩
曲美娜
尚振涛
JIN Tan;MA Xin;HU Hao;QU Meina;SHANG Zhentao(College of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082;National High-efficiency Grinding Engineering Technology Research Center,Hunan University,Changsha 410082;AECC South Industry Company Ltd.,Zhuzhou 412008)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2022年第15期55-62,共8页
Journal of Mechanical Engineering
基金
中国航发集团产学研合作资助项目(HFZL2019CXY007)。
关键词
镍基高温合金
多孔金属结合剂砂轮
磨削液
对流换热系数
缓进深切磨削
nickel based super alloy
porous metal bond wheel
grinding fluid
convection heat transfer coefficient
creep-feed grinding
