Study On The Oil-based SiC Grinding Fluid

As an integral part of precision machining field,oil-based grinding fluid possesses not only the effect of grinding removal,but also the properties of cleaning,lubricating and anti-rust.Silicon carbide(SiC)has many excellent properties,such as high hardness,strength retention at elevated temperatures,excellent wear and oxidation resistances.At the same time,it has higher grinding efficiency compared with corundum,but relative cheaper price than diamond.Thus,SiC has become an ideal choice of abrasive in abrasive products.Because the surface of SiC is super-hydrophilic,the researches about dispersion of SiC powder were limited in aqueous or ethanol media,and few reports have mentioned the dispersion of SiC in base oils.However,an important aspect of grinding fluid preparation is the achievement of high concentrated,well-dispersed and stable slurry.In this paper,PAO6 and TMPTO were selected as the dispersion medium;Span60,Tech-5080 and Tech-6300 were used as dispersants;3-aminopropyl triethoxysilane(KH550)and 3-mercaptopropyl trimethoxysilane(KH590)were adopted as preliminary modifiers and hexadecyl iodiele as the second modifier to improve the hydrophobic surface properties of SiC powder.In order to assess the effects of dispersants,modifiers and technological parameters on the preparation of oil-based SiC grinding fluid,a systematic investigation such as viscosity and stability measurements,contact angle measurement,FTIR,XRD,SEM and so on were studied.According to the results,the solvent containing 50vol% PAO6 is the best dispersion medium to prepare well-dispersed and stable SiC slurry.Among Span60,Tech-5080 and Tech-6300,Tech-5080 has the greatest effect on the dispersion of SiC slurry and the optimum dosage was 0.5wt%.In the treatment schemes of silane coupling agent,the results showed that KH590 has a better effect than KH550 for the hydrophobic modification of SiC,and the contact angle improved most(106.8°)after SiC powder was reacted with 0.3 g KH590 at 75? in aqueous/ alcohol solution for 4h.After being modified by hexadecyl iodiele,the contact angle was increased to 127.5°.Moreover,the XPS and FTIR analysis results verified that the modifiers were covalently bonded to the SiC surface.