Grinding forces in micro slot-grinding (MSG) of single crystal sapphire. (January 2017)

• Record Type: Journal Article
• Authors: Cheng, J.; Wu, J.; Gong, Y.D.; Wen, X.L.; Wen, Q.
• Is Part Of: International journal of machine tools & manufacture. Volume 112(2017)
• Page Start: 7
• Page End: 20
• Publication Date: 2017-01
• Subjects: Micro-slot grinding(MSG) -- Single crystal sapphire -- Grinding force -- Crystalline effect; Machine-tools -- Periodicals; Manufacturing processes -- Periodicals; Machines-outils -- Périodiques; Fabrication -- Périodiques; Electronic journals; 621.902
• DOI: 10.1016/j.ijmachtools.2016.10.004
• Languages: English
• ISSNs: 0890-6955

Abstract

Abstract: Micro-slot grinding (MSG) is an important processing method for the micro-machining of hard brittle crystalline materials. Modelling the MSG of crystal material is necessary to understand its precision micro-machining aspects. In this paper, a predictive model is developed for the grinding force in MSG in three different orientations of single crystal sapphire: the C-orientation {0001}, A-orientation {11 2 ¯ 0} and R-orientation {1 1 ¯ 02} are established. The crystalline effects of the density of Al +, − Al + and D Al + ; the density of O − hollows D O − ; the number of crystal layers ζ ; and the weak shape of different orientations are incorporated. Three group experiments (144 paths) are performed, and the differences in the grinding forces from three orientations, {0001}, {11 2 ¯ 0} and {1 1 ¯ 02}, are discussed. The grinding forces of the A-orientation {11 2 ¯ 0} are higher than of the other two orientations {0001} and {110 2 ¯ }, and the number of crystal layers ζ is shown to play a vital role in determining the grinding force required for MSG of sapphire. The force ratio r F ( F x / F y ) is between 0.6 to 0.8, and the r F of {110 2 ¯ } is more stable than for the {11 2 ¯ 0} and {0001} orientations. A comparison with existing models and experimental data shows that the model used in this study fits the experimental data better, especially at lower feeding rates. Highlights: A predictive model of grinding force in MSG of three different orientations of single crystal sapphire: C-plane {0001}, A-plane {11 2 ¯ 0} and R-plane {1 1 ¯ 02} are established. The MSG experiments results show that {0001} orientation could produce comparatively smaller grinding force which is almost 80% of the {11 2 ¯ 0} and 50%~65% of {11 2 ¯ 0}. The force ratio rF (Fx /Fy ) is between 0.6 to 0.8 for three orientations. It is disorder when the undeformed chip thickness hm is less than 10 nm. {11 2 ¯ 0}