The effect of concentration of coco amido propyl betaine (CAPB) as green additive in bio-based coconut oil lubricant on the machining performance of Inconel 718

The rising concern on the detrimental effects of mineral oil-based metal cutting fluid on the environment has open the way for a more natural and environmentally friendly alternative such as vegetable oils. Application of these biodegradable fluids in machining in place of mineral oil-based metal cutting fluids has been proven to produce equal or even better results than the conventional cutting fluids. Furthermore, combining bio-based cutting fluid with minimum quantity lubricant (MQL) system further improves machining results and reduces machining cost while minimizing the negative impacts of cutting fluids to the environment. However, the bacterial contamination risk and inability to withstand high impact during machining makes bio-based fluid a less preferable cutting fluid choice. Anyhow, with proper fluid formulation, the contamination risk of bio-based cutting fluids can be lowered and their cooling and lubrication ability enhanced. To date, there are currently lack of research works and findings on the lubrication ability of bio-based cutting fluids. Hence, in this work, the author tests the contrariety of bio-based oil formulation using coconut oil with different concentrations of coco amido propyl betaine (CAPB) while machining Inconel 718. The experiment settings was kept constant at 80 m/min cutting speed, 0.2 mm/rev feed rate and 0.1 mm depth of cut, and the effects on cutting tool and surface finish were observed. Experimental result revealed that higher concentrations of CAPB reduces tool wear and surface roughness.