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In this paper, the fouling of sintered [alpha]-alumina membranes by an uncontaminated semisynthetic metalworking fluid (MWF) is addressed. Experimental evidence of the form of flux reduction curves, scanning electron microscope images of the membranes, and MWF particle size measurements is used to identify two fouling mechanisms, pore blocking and partial pore blocking, as the major contributors to flux decline. A probability-based mechanistic model is developed based on the time-dependent particle size distribution and membrane pore sizes. The model is fitted to experimental data from two commonly used membrane pore sizes with good agreement. Partial blocking is shown to be a predominant first step in the pore blocking mechanism in microfiltration of semisynthetic MWFs due to the tortuous nature of the pores present in sintered ceramic membranes. [DOI: 10.1115/1.2953234] Keywords: microfiltration, metalworking fluids, cutting fluids, membrane fouling

Membrane microfiltration is a promising technology that has been shown to extend metalworking fluid (MWF) life by eliminating contaminants while allowing the fluid to stay in use. However, the efficacy of this technology is compromised by the clogging of the filter pores in a process known as membrane fouling. In this paper the fouling issue is addressed by the development of a semi-synthetic MWF specifically designed to not foul microfiltration membranes. The composition of the designed MWF is discussed and compared with a commercial MWF. Cross-flow microfiltration fouling tests were carried out in low-pressure, high-velocity conditions on ceramic [alpha]-alumina membranes. Several common MWF components are shown not to be factors of membrane fouling on these membranes. The flux of the designed fluid was found to reach an immediate steady state at about twice the value of the steady-state flux of the tested commercial fluid. Scanning electron microscope imaging was used to further evaluate membrane fouling by each fluid. The machining capabilities of the designed fluid were examined in terms of cutting forces and machining temperature. [DOI: 10.1115/1.2401207] Keywords: microfiltration, membrane fouling, metalworking fluids

The fluid flow problem in a traditional electrolytic in-process dressing (ELID) system is analyzed and solved numerically. The predicted mean velocity profiles in the dressing zone show flow patterns that are in good agreement with the mean velocity distributions for plane laminar/turbulent Couette flows observed in the experiments. The computational results reveal that insufficient electrolyte supply rate is the cause of the failure of the traditional ELID system for high-speed grinding. Results also show that to obtain effective high-speed ELID grinding, a consistent high inlet electrolyte velocity or supply rate is required. For the foil ELID system, governing equations describing the fluid flow in the dressing zone and the foil elastic deformation are formulated. Analytical solution based on unidirectional flow model for the problem is presented and effects of wheel surface speed and foil tension on the performance of the dressing system are discussed. It is shown that the foil ELID system has the potential to be effective for high-speed grinding with low electrolyte supply rates. The results will be useful to the development of new machine systems and processes for high-speed grinding. [DOI: 10.111511.1765152]