Abrasive machining with MQSL.

摘要

Grinding and polishing of engineered components are critical aspects of the precisionmanufacturing of high performance, quality assured products. Elevated processtemperatures, however, are a common and for the most part undesirable feature ofthe grinding process. High process temperatures increase the likelihood ofmicrostructural change within the immediate subsurface layer and are detrimental tothe strength and performance of the manufactured products. Increasing processingcosts and tighter environmental legislation are encouraging industry to seek innovativefluid application techniques as significant savings in production can be achieved.In this context, and with sponsorship from three industrial partners, namely; FivesCinetic, Fuchs Lubricants plc and Southside Thermal Sciences Ltd, and also from theEngineering and Physical Science Research Council (EPSRC), this research aimed todevelop an understanding of Minimum Quantity Solid Lubrication (MQSL) as a methodfor abrasive machining, with particular reference to the control of surfacetemperatures.Improving the lubricity of Minimum Quantity Lubrication (MQL) fluids reduces thefrictional source of process heat and controls the finish surface temperature. Theapplication of effective solid lubricants is known as Minimum Quantity SolidLubrication (MQSL). Molybdenum Disulphide (MoS2), Calcium Fluoride (CaF2), andhexagonal Boron Nitride (hBN) were compared against a semi-synthetic water solublemachining fluid (Fuchs EcoCool). A series of Taguchi factorial experimental trialsassessed their performances through ANOVA (ANalysis Of VAriance) statistical method.The hBN produced the lowest grinding temperatures of the solid lubricants tested,although they still remained higher than those achieved using the EcoCool control.The reduction of the machining fluid enabled a Charged Coupled Device (CCD) sensorto be fitted into the grinding machine. The recorded movement in the emittedspectrum from the grinding chips was compared to experimental and modelledprocess temperatures. This showed that the wavelengths of the chip light correlated tothe temperature of the finish grinding surface. This greatly contributed to determiningthe feasibility of constructing a non-destructive, non-invasive, thermally-adaptivecontrol system for controlling grinding surface temperatures.