Investigation of Cutting Tools and Working Conditions Effects when Cutting Ti-6al-4V using Vegetable Oil-Based Cutting Fluids

Power consumed in metal cutting is typically converted into heat near the cutting tool edge. Cutting fluids are then provided to a cutting zone in order to improve the tribological characteristics of machining processes and to dissipate the generated heat. The use of conventional cutting fluids however has lately been questioned due to the adverse impact on the environment and human health. Therefore, trends are directed to various alternatives such as vegetable oils (VOs). VOs offer a combination of good biodegradability and high lubricity, eco-friendly and compatibility with additives, low toxicity and volatility, high flash points and high viscosity indices. This paper details preliminary experimental results when turning Ti-6Al-4 V. The impact of VO-based cutting fluids, cutting tool materials and working conditions were investigated. Two sets of experimental plans were designed comprising 25 and 27 tests with analysis of variance (ANOVA) employed to evaluate the effect of process variables on Ra and tool flank wear. In general, surface roughness Ra ranged between 0.56 μm and 1.81 μm and statistical analysis showed that the main contributing factor for Ra is feed rate having a high Percentage Contribution Ratio (PCR) of 94.4%. Noticeable increase in tool tip flank wear was recorded when higher cutting speeds were used.