Investigation of hole quality in rotary ultrasonic drilling of borosilicate glass using RSM
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The present article emphasizes on reducing the edge chipping and taper during rotary ultrasonic drilling of one of the most demanded ceramic glasses “BK-7.” Statistical tools of design of experiments and backing plate were adopted as two distinct approaches to curb the chipping damage. Central composite design has been conjugated with desirability function for framing the design matrix. This investigation also emphasizes to study the effect of process variables—spindle speed, ultrasonic power and feed rate—on the chipping width (CW) and taper (T). After developing the second-order regression models for the CW and T, analysis of variance was used to check the fitness of regression models and recognizing the significant model terms. Then impact of each process parameter was analyzed on responses of interest through 3-D surface plots. The feed rate came forth as the most dominating factor by having maximum influence over the qualitative aspects “CW” and “T” of the drilling process. Interactions of higher rpm and power with lower feed effectively reduced the CW and T. The backing material, employed during main experimentation, also proved its effectiveness to reduce CW when main experiments results were compared to the results of pilot experimentation, which was performed without backing plate. Scanning electron microscope (SEM) was used to analyze the different tool wear modes and microstructure of machined surfaces. Tool weight measurement revealed the dominance of bond fracture and grain fracture during the early stage of the drilling process. Apart from brittle fracture, SEM also affirmed the presence of plastically deformed regions over the machined surfaces. Little deviations between the predicted values and experimental values during the confirmatory tests validated the prediction accuracy of regression models at 95% confidence level.
KeywordsChipping Taper Optimization RSM Desirability Wear Ultrasonic Drilling
The authors acknowledge the National Institute of Technology, Kurukshetra, for providing the requisite facilities for this research work.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest to report.
- 1.Barahimi V, Farahnakian M (2016) Experimental investigation of the surface roughness in grinding of BK7 optical glass in brittle mode. J Mod Process Manuf Prod 5:33–41Google Scholar
- 6.El-Hofy HA-G (2005) Advance machining processes. McGraw-Hill, New YorkGoogle Scholar
- 34.Santhanakrishnan M, Sivasakthivel PS, Sudhakaran R (2017) Modeling of geometrical and machining parameters on temperature rise while machining Al 6351 using response surface methodology and genetic algorithm. J Braz Soc Mech Sci Eng 39:487–496. https://doi.org/10.1007/s40430-015-0378-5 CrossRefGoogle Scholar
- 35.Sematech NIST (2006) Engineering statistics handbook. The National Institute of Standards and Technology (NIST)Google Scholar
- 36.Montgomery DC (2000) Design and analysis of experiments, 5th edn. Wiley, LondonGoogle Scholar
- 46.Churi N, Pei ZJ, Shorter D, Treadwell C (2009) Rotary ultrasonic machining of dental ceramics. Int J Mach Mach Mater 6:270–284. https://doi.org/10.4028/www.scientific.net/MSF.532-533.361 CrossRefGoogle Scholar
- 52.Fernando PKSC, Pei Z, Zhang MP, Song X (2017) Rotary ultrasonic drilling of CFRP: effect of process parameters on delamination. In: Proceedings of ASME 2016 international manufacturing science and engineering conference, pp 1–6Google Scholar