Parametric experimental study and design of experiment modelling of sapphire grinding

Abstract

a b s t r a c tThis study investigates and models the grinding process of single crystal sapphire. Five parameters: the wheel speed, the feed speed, the vertical feed, the ultrasonic assistance and the crystallographic direction were considered via a design of experiments (DoE) approach. The responses were multiple but can be divided in three groups: the process, the machine and the grinding quality. DoE results revealed that the parameters interact in a complex manner and depends on the responses. Therefore, to gain a better understanding of the grinding process of sapphire, the interactions between parameters have also to be taken into consideration. It was found that three main parameters have the largest influences on the tangential grinding forces: the wheel speed, the feed speed and the vertical feed. In contrast, the median defect area is mainly impacted by the quadratic effects of the wheel speed and vertical feed followed by various interactions. After an optimization procedure, the second optimum for the tangential forces was found to be very close to the best optimum for the median defect area. The optimum solution is: a wheel speed of 7 0 500 rpm, a feed speed of 60 mm/min, a vertical feed of 12.5 mm/pass, no ultrasonic assistance and grinding along the c-axis. This set of parameters was validated with additional and repeated tests on both Verneuil and Kyropouloas sapphire. Finally, it came out that the optimum solution has also a very good productivity.

Dynamic coal blending under sustainability concerns: a case study from the Indian steel industry

“…Griffiths et al (2016) consider 3D printed products for the environmental and economic assessment at the design stage for the part optimization using DOE. Wasmer et al (2017) study a parametric experiment for sapphire grinding under multiple responses. Lujan-Moreno et al (2018) tune hyperparameters through a random forest case study and demonstrate the use of DOE and RSM under a machine learning algorithm.…”

“…(2016) consider 3D printed products for the environmental and economic assessment at the design stage for the part optimization using DOE. Wasmer et al . (2017) study a parametric experiment for sapphire grinding under multiple responses.…”

Modelling and monitoring of abrasive finishing processes using artificial intelligence techniques: A review

“…Performance prediction of any machining process such as surface roughness, material removal, depth of cut, etc. could be modelled [171][172][173] using ML techniques by correlating to machining parameters and sensor data as shown in Fig. 26 Fig.…”

Investigation into the anisotropy of cross-grinding surface quality in C- and M-planes of sapphire

“…31 This study preliminarily stated the influence of crack orientation on the machined surface roughness for different crystal planes of sapphire. Furthermore, Wasmer et al 32 conducted parametric experiments on A-plane of sapphire and found that grinding along the c -axis suffers a reduced grinding force compared with that along the m -axis. Mohammadi and Patten 33 investigated the effect of crystal orientation and laser power on the BDT depth of sapphire by laser-assisted scratching tests, and it is confirmed that different crystal orientations on C-plane have different BDT depths no matter with or without laser assist.…”