Changes in Mechanical, Rheological and Morphological Properties of Glass-Fiber Reinforced Poly(oxymethylene) Composite after Ageing in Laboratory Environment and Water

In this study, the changes in mechanical, rheological and morphological properties of glass-fiber reinforced poly(oxymethylene) composite after ageing were investigated. Samples were prepared with plastic injection molding method. Ageing process was done by waiting samples at laboratory temperature and water during 28 days. Tensile and 3 point flexural tests were done to determine the mechanical properties, melt flow index (MFI) was measured to determine the rheological property and scanning electron microscopy (SEM) was used to observe the morphological structure. From experimental results, it was seen that mechanical, rheological and morphological properties were affected by the ageing environment. It was found that mechanical properties of aged samples were lower than that of unaged sample. The most decrement in the mechanical properties was occurred at the aged in water samples. Ageing process increased MFI value

Fuzzy logic and regression modelling of cutting parameters in drilling using vegetable based cutting fluids

51-58In machining industry, cutting fluids have an important role due to their lubrication, cooling and chip removal functions. Using of cutting fluids can improve machining process efficiency, tool life, surface quality and it can reduce cutting forces and vibrations. However, health and environmental problems are encountered with the use of cutting fluids. Therefore, there has been a high demand for using environmentally friendly cutting fluids such as vegetable based cutting fluids in order to diminish these harmful effects. For this purpose, two different vegetable based cutting fluids are used to improve machining performance. This study focuses on prediction of thrust force and surface roughness with vegetable based cutting fluids (VBCFs) using fuzzy logic and regression. The drilling experiments are conducted according to Taguchi’s L9 orthogonal array. Thrust force and surface roughness during drilling of AISI 304 with HSS-E tool are measured. Spindle speed, feed rate and drilling depth are considered as machining parameters. A model depended on fuzzy logic approach is established and the results obtained from fuzzy logic are compared with the results based on regression and experiment. Effectiveness of fuzzy logic and regression models has been determined by analyzing correlation coefficient and by comparing experimental results. Fuzzy logic models give closer values to experimental measured values than regression models. It has been concluded that fuzzy rule based modelling can be used to predict the thrust force and surface roughness successfully

Application of cutting fluids in micro-milling - A review

This article provides an overview of micro-milling operation with a focus on cutting fluids and reviews and discusses dry machining, flood, cryogenic cooling, usage of minimum quantity lubrication (MQL) approach, nanoparticle suspensions, and vegetable oils. In conclusion, the article highlights the future trends and research gaps in field of micro-milling with cutting fluids. Based on works, it can be concluded that researchers explore substitutes for traditional cutting fluids in micro-milling, including vegetable oils, nanofluids, cryogenics, solid lubricants, and de-ionized water. Most cutting fluid studies have focused on micro-milling of aluminum, steel, and titanium, with surface roughness being the most measured output in micro-milling work involving cutting fluids. Overall, the article highlights the need for further research in various aspects of micro-milling operations with cutting fluids, including the development of new cutting strategies, the optimization of cutting fluid delivery methods, and the evaluation of various machinability parameters

Experimental evaluation of eco-friendly hybrid cooling methods in slot milling of titanium alloy

The positive effects of cutting fluids on the machinability performance are well known in machining industry. However, it is also known that their use causes environmental and health problems. Moreover, manufacturers are faced with strict environmental regulations in order to employ dry machining, which is not efficient especially in machining of difficult-to-cut materials such as titanium alloys. Therefore, machining industry developed alternative green machining solutions such as minimum quantity of lubrication, vegetable based cutting fluids, cryogenics and hybrid cooling (combination of cryogenics and minimum quantity of lubrication). Up to now, no work has been documented in the literature on comparison of cryogenics and hybrid cooling with minimum quantity of lubrication. Furthermore, as no information regarding the effects of hybrid cooling on workpiece temperatures during milling of titanium alloy is available, this research aims to demonstrate the feasibility of implementing cryogenics and hybrid cooling method in slot milling of titanium alloy. Thus, the aim of this experimental study was to determine the machining performance of titanium alloy under various green lubricating/cooling methods. In order to do so, minimum quantity of lubrication, cryogenic cooling by spraying liquid nitrogen, cryogenic cooling by spraying carbon dioxide, simultaneous spraying of carbon dioxide and minimum quantity of lubrication, and simultaneous spraying of liquid nitrogen and minimum quantity of lubrication were applied during slot milling process under different cutting speeds. The performance of these methods was evaluated by measuring tool wear, temperature, cutting forces and surface roughness. The results showed that the efficiency of cryogenic cooling was based on the cutting speed where better results were obtained at higher speeds. It was also concluded that the simultaneous spray of cryogenic fluid and minimum quantity of lubrication improved the machinability of titanium alloy as compared to only spray of cryogenics because of both lubricating and cooling effects. In terms of environmental impact of machining operations, hybrid cryogenic methods offer an efficient solution to improve the process sustainability towards cleaner production since the coolant volume is reduced substantially compared to conventional cooling methods decreasing pollutants, and lung and skin diseases experienced by the workers in production facilities. Results showed that the combination of cryogenic and minimum quantity lubrication method provided a balance between productivity and environment. Hybrid method improved the productivity of milling process in terms of cutting speed, tool life, and cost while increasing environmental protection and operator health and reducing material waste