Effect of Fluid Media on Abrasive Polymeric Composite Products with Various Elasticity

The fluid media influence studies established that only water substantially affects epoxy-based rigid composites; the effect of kerosene and oil on products modified with acetur and, particularly, polyethylsiloxane is insignificant. Besides, bending strength and hardness change approximately in proportion to the level of saturation. As for elastic composites, the level of saturation depends on the fluid type and laprolate rubber component in the bond; the water effect is substantially higher as compared to other fluids. The more laprolate, the higher the effect of fluids is. Due to low viscosity, water enters pores easily, dissolves unpolymerized material areas, breaks adhesive bond, and deteriorates composite quality. Thus it is necessary to foresee use of fluid media according to the particular parameters of the composites and fluids, as well as service life

Bending deformation analysis of gear hone tooth lateral faces

Gear hones are used for finish machining of hardened gear tooth lateral faces by the generating method. In service, due to penetration of abrasive grains into metal, wear and running-in of the tool material, especially in the case of elastic binding agents, the tooth contact takes place not in a point, but in an ellipse area. The total bending deformation of a hone tooth in the contact point is a sum of the fixed tooth bending deformation and the deformation, characterizing the tooth root travel in a hone rim. The calculations make it evident that hone tooth bending deformation value depends on the contact point vertical position; it drops by a factor of 400 – 500 from the lower contact point to the top. Besides, deformation increases by a factor of 60 with decrease of the elasticity modulus. The rim part adjacent to a tooth is also considered during analysis of the second component of the total tooth bending deformation, characterizing the tooth root elastic strain. With the tooth height increase, this deformation value increases by a factor of 4 – 20 and significantly (by an order of magnitude) increases with the elasticity modulus drop. Bending deformation analysis results of gear hone teeth are applied for studying their operation capabilities, as well as development of geometry and compound specifications

Effects of forming agents on performance of highly-porous abrasive tools

Quality assurance and processing capacity are essential performance parameters of abrasive tools. It is of prime importance for grinding wheels operating at a speed of 35–60 m/s. In this case, opportunities to increase grinding efficiency without burns are associated with using high-porosity and low-hardness wheels. Artificial pore-forming agents are used to manufacture tools. The introduction of pore-forming agents decreases grinding forces and increases the maximum grinding depth without burns. The grinding ratio decreases as the content and grit size of pore-forming agents increase. Since the introduction of pore- forming agents with the grit size exceeding that of the abrasive material increases the distance between the abrasive material’s grains, the surface roughness of grinding with high-porosity wheels is slightly higher, which requires using wheels with a lower grit size of the abrasive material. In general, a possibility to apply deeper grinding without burns emerges, which increases capacity, ensuring the required metal-surface quality