Optimization of cutting fluids and cutting parameters during end milling by using D-optimal design of experiments

The use of synthetic cutting fluids is nowadays limited due to the adverse effects such as health of the operator, environmental and economic reasons. In order to diminish these negative effects, bio-based cutting fluids are used. Bio-based or vegetable based cutting fluid is considered environmentally friendly and sustainable. Vegetable based cutting fluids have some characteristics such as biodegradability, less toxicity and renewability. This study deals with the assessment of vegetable based cutting fluids for end milling. For this purpose, effects of cutting fluid types are investigated as a function of three milling factors (cutting speed, depth of cut and feed rate) on process responses (specific energy, tool life and surface roughness). D-optimal method is conducted to develop mathematical models for process responses. Variance analysis shows that specific energy, surface roughness and tool life can be predicted effectively with quadratic models. Furthermore, mono and multi objective optimization studies are conducted using specific energy, surface roughness and tool life as primary or secondary objectives. From results of the optimization, various conclusions are drawn about effects of the milling parameters and the cutting fluid types on the milling performance criteria. The most appropriate cutting fluid during milling of AISI 304 material is selected in accordance with energy, tool life and surface roughness.