State-of-art-review of electrochemical honing of internal cylinders and gears

Abstract

This paper is an attempt to present a state-of-the-art review of two major applications of electrochemical honing (ECH) for internal cylinders and gears, which are the most commonly used parts in numerous engineering applications. ECH is a hybrid process of electrochemical machining (ECM) and mechanical honing, combining the fast material removal capabilities of ECM and controlled functional surface generating capabilities of mechanical honing in a single operation. ECH is a precision micro-finishing process capable of producing excellent surface quality having a cross-hatch lay pattern required for lubricating oil retention, compressive residual stresses required for the components subjected to cyclic loading, and completely stress-free surfaces. Furthermore, it provides these benefits productively. It makes ECH an ideal choice for superfinishing, improving the surface integrity, and increasing the service life of the critical components such as internal cylinders, transmission gears, carbide bushings and sleeves, rollers, petrochemical reactors, moulds and dies, gun barrels, etc., most of which are made of very hard and/or tough, wear-resistant materials generally susceptible to heat distortions. Consequently, ECH finds widespread use in the automobile, avionics, petrochemical, power generation, and fluid power industries. This paper presents a detailed description of the process principle, parameters, capabilities, equipment details, applications, and comprehensive literature review of past research work on the ECH of internal cylinders and gears along with some directions for future research with an objective to revive the interest of the global research community to mature this process further.