Effect of the Grinding Conditions and the Characteristics of Abrasive Tool on the Cutting Force Components for a Microporous Coating on a Restored Part

Abstract—Wear-resistant microporous nickel-based coatings belong to the group of difficult-to-process materials, the abrasive processing of which encounters significant difficulties. The main causes of the poor machinability of these coatings by grinding are the rapid loss of the cutting properties of abrasive wheels due to their bluntness and the active adhesion of coating particles to the working surface of the tool. A method is proposed to increase the efficiency of the coarse grinding of microporous coatings by searching for optimum technological factors that ensure the maximum durability of abrasive tool and low energy consumption. The cutting ability of fused silica wheels during circular external infeed grinding of microporous coatings is studied. The dependences of the radial (P_y) and tangential (P_z) components of the cutting force on the operating factors, namely, the cutting speed, the rate of part rotation, and the radial feed, and the characteristics of the wheels, namely, the grain size and the hardness, are investigated. The technique and results of studying the infeed grinding of microporous coatings using an active designed experiment are presented. A fractional factorial experiment conducted according to the 2^5–2 scheme is used as an experimental plan. The values of technological factors and the levels and ranges of their variation are given. The levels of the factors are justified. The following experimental conditions are described: the sizes and characteristics of grinding wheels (GWs) are justified, the chemical compositions of the processed plasma-sprayed coatings, and the sample sizes. Statistical analysis has been performed, and mathematical models have been developed to reflect the influence of the cutting conditions and the characteristics of wheels on a response surface (grinding force components P_y and P_z). The obtained mathematical models are analyzed, and the obtained results are interpreted from a technological viewpoint. The further direction of using the obtained models to solve the problem of optimizing the cutting conditions and the characteristics of abrasive tool in terms of maximizing the durability of GWs is shown.