Effects of Environmental-Friendly Cutting Fluids on Surface Roughness and Tool Wear in Laser-Assisted High Speed Milling of Aluminium Alloy and 316 Stainless Steel

• Main Author: Farhana, Yasmin
• Format: Thesis
• Language: English
• Published: Universiti Malaysia Sarawak (UNIMAS) 2021
• Subjects: TJ Mechanical engineering and machinery; TS Manufactures
• Online Access: http://ir.unimas.my/id/eprint/35692/1/Farhana%20Yasmin.pdf; http://ir.unimas.my/id/eprint/35692/
• Institution: Universiti Malaysia Sarawak

Laser-assisted high speed milling is a subtractive machining method that employs laser to thermally soften material’s surface in order to enhance machinability at high material removal rate with improved surface finish and tool life. Its counterpart includes an ultrasonic-assisted milling where ultrasonic source is connected to the cutting tool. It has demonstrated effective in terms of acquiring good surface topography and high surface finish. However, the application of the latter is limited at low speed and low feed rate, thus not widely applicable for high volume production. In this study, an ultrasonic-induced droplet delivery method and minimum quantity lubrication (MQL) are proposed. To minimize environmental and food insecurity of edible oils, a water-soluble sago starch cutting fluid is newly prepared. Thus, the primary objective of this study is to experimentally investigate the effects of ultrasonic-induced droplet vegetable-based cutting fluid and MQL water-soluble sago starch cutting fluid on surface roughness of alloys and tool’s flank wear using response surface methodology (RSM), and predict the machining characteristics by extreme learning machine (ELM). The entire experimentation is conducted based on a laser-assisted high speed milling of aluminuim alloy and 316 stainless steel. The experimental setup consists of a mini milling machine, a cutting fluid delivery mechanism, and a laser machine. In this study, the feed rate, cutting speed, laser power and flow rate of droplet are considered as the major input process parameters. In order to observe the comparison, the experiments with same machining parameters are carried out with conventional methods. Ultrasonic-induced droplet cutting fluid shows favourable reduction in surface roughness and flank wear by 14.74% and 6.57%, respectively. Whilst water-soluble sago starch cutting fluid demonstrates the reduction in surface roughness and flank wear by 48.23% and 38.43%, respectively. Based on RSM, the system errors between the results of measured values using verification experiments and predicted values of the regression model for surface roughness and flank wear are found out to be within only 4%. Furthermore, using the ELM, the obtained data is modeled to predict surface roughness and flank wear and showed good agreement between observations and predictions for both proposed methods.