Експериментальне дослідження впливу зернистості абразиву силікатної пасти на якість поверхонь тертя

Abstract

Currently, many technological methods have been developed to change the structure and properties of surface layers of metal in the desired direction or to create layers with predefined properties. The use of these methods can increase wear resistance, resistance to fatigue and other performance properties of automotive parts. One such method is grinding with abrasive compounds. Grinding technology consists in applying abrasive compositions on the surface of the part and subsequent machining using special devices.The results of experimental research of influence of granularity of abrasive of silicate paste on quality of friction surfaces are resulted in work. Silicate compositions with electrocorundum abrasive of different grain size were made for the study. In order to compare the performance of silicate paste, the existing abrasive pastes «KT» with abrasive titanium carbide abrasive of similar grain size were selected. The research was performed on a special installation, which allows to reproduce with high accuracy the process of processing the abrasive composition in the laboratory. The evaluation was based on the duration of grinding, metal removal and surface quality. Stabilization of the coefficient of friction showed the completion of the grinding process.The study confirms that with increasing grain size of the abrasive silicate composition increases the time of formation of the surface layer and the amount of metal that is removed. It is proved that the high quality of the surface after treatment with silicate composition is due to the appearance in the grinding process of amorphous silica (SiO2), which enhances the work of abrasive grains and reduces the action of the scratching abrasive. Under the action of abrasive particles, SiO2 enters the depressions of the treated surface and adheres to the surface. It is established that the productivity of grinding with silicate composition is 1.5 times higher than when treating surfaces with «KT» paste. It was found that when treating surfaces with a silicate composition with electrocorundum abrasive, the removal of metal is 1.8 times less than when treating with «KT» paste. It is proposed to assign an allowance for treatment with silicate paste from 0.035 to 0.07 mm.