Effective application of scraper board in grinding. (December 2017)

• Record Type: Journal Article
• Authors: Majumdar, Sujit; Kumar, Suraj; Chakraborty, Samik; Roy, Debasish
• Is Part Of: Tribology international. Volume 116(2017)
• Page Start: 120
• Page End: 128
• Publication Date: 2017-12
• Subjects: Grinding -- Fluid delivery -- Scraper board -- Critical region -- Grinding force -- Surface texture -- Grinding ratio -- Specific energy -- Grinding chip -- ANOVA -- Regression model; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2017.07.009
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: This experimental work is aimed at characterizing the effect of scraper board (SB) in reducing the rotating air layer around a grinding wheel and introducing the better method of application of scraper board and fluid delivery into the grinding zone. Zero pressure at the grinding zone is reported to achieve by placing the scraper board at an optimal location along the wheel periphery. The grinding ratio improved by 35.6% and 119%, surface roughness decreased by 36% and 54.2% while the requirement of specific energy is reduced by 50.8% and 57.3% when scraper board is positioned at the critical distance in comparison to the 57.5° position and no scraper board respectively. Highlights: A new method for effective lubrication between wheel-grits and workpiece. The critical region on the wheel periphery where the minimum pressure of rotating air layer exists. So when a grinding fluid jet is impinged into this zone, less hindrance is experienced by the jet and hence better lubrication into the mating surfaces becomes possible. Substantial depletion of air layer can be possible with the use of a scraper board located up to 20° ahead of wheel-workpiece contact area. Regeneration of this air layer can recur after 20° of angular position. By impinging the coolant jet into critical region or no-air region, grinding tests have been performed. The surface roughness and requirement of specific energy is reduced by 54.2% and 57.3% respectively and grinding ratio improved by 119% compared to the conventional flood cooling where no scraper board is used. This paper also suggests a model to quantify the pressure at the grinding zone with respect to the position of scraper board which otherwise is difficult to learn by practical experiment and which may be a valuable data to determine force of jet of cutting fluid at which it must fall on the wheel.