Effects of CuO and graphite additive nanofluid lubricants on machining performance in the milling of AISI 329 stainless steel

In this thesis, AISI 329 stainless steel was milled under minimum quantity lubrication (MQL) and nanoparticle added MQL (NanoMQL) conditions. In this context, copper oxide (CuO) and graphite (Grpt) were preferred as nanoparticles. In addition, nanoparticle mixtures were prepared by adding 0.6% vol into the vegetable-based oil. The thesis study was handled in two stages. In the first stage, three different surfactants (cetyltrimethylammonium bromide - CTAB, polyvinylpolypyrrolidone - PVP and sodium dodecyl sulfate - SDS) were added to the CuO nanofluid mixtures in the same proportions and a series of experiments were carried out according to the Taguchi L9 experimental setup. PVP surfactant determined according to the obtained surface roughness (Ra), cutting temperature (T) and cutting tool wear results was used in the second stage of the thesis. In the second stage of the study, machinability performance tests of CuO and Grpt nanofluids at different mixing ratios with PVP surfactant added were carried out. In this context, cutting condition (CuO, Grpt, CuO/Grpt), mixing ratio (1:1, 1:2, 2:1, 1:3 and 3:1) and cutting speed (120, 160 and 200 m/min) were used as input parameters in experimental design. Feed rate (0.1 mm/rev) and cutting depth (0.5 mm) were kept constant in the experiments. Analysis of variance (ANOVA) was used to determine the effect levels of the input factors. According to the results obtained from the thesis study; PVP surfactant showed the most effective tribological performance in nanofluid preparation. In addition, compared to the dry condition CuO/Grpt+PVP (1:3) hybrid nanofluid was reduced the surface roughness and cutting temperature by 48.97% and 56.57%, respectively.