Optimizing Microporous Coating Grinding Operation according to the Cost Criterion

Abstract—Significant challenges, including rapid wheel loading and reduced grinding wheel life, exist in the cylindrical external grinding of automotive, tractor, agricultural and construction equipment shaft journals rebuilt using gas-thermal spray deposition techniques. This results in frequent machine stoppages for wheel dressing, which greatly increases abrasive tool consumption and grinding time losses, resulting in a significant increase in abrasive processing costs. The underlying cause of these phenomena is attributed to the unique physical and mechanical characteristics of the coatings, including high porosity, the presence of oxides and slag inclusions, and high adhesive and chemical activity. The study underscores that a promising approach to enhancing the efficiency of plunge grinding for coatings and attaining high technical-economic performance is the optimization of abrasive processing. This paper presents the results of optimizing the cylindrical plunge grinding process for microporous nickel-based coatings. A set of parameters required for optimizing the grinding operation based on technological cost criteria is developed. A system of technical constraints is also developed to optimize cutting conditions and grinding wheel characteristics. The study deals with the problem of how to achieve the minimum cost of the machined surface while maintaining the specified parameters of the grinding process. A mathematical model of the grinding process is developed as an integral part of the optimization problem. The objective function (technological cost) is optimized using the linear programming method. The optimal cutting parameters and grinding wheel specifications (grain size and hardness) that minimize the technological costs of grinding are determined. The proposed methodology can be used to determine the optimal parameters for grinding microporous coatings on various repaired components, such as crankshaft and camshaft journals in internal combustion engines. Minimal processing costs can be reliably achieved in plunge grinding of microporous thermal spray coatings by taking all process influencing factors into account.