Global strategy of grinding wheel performance evaluation applied to grinding of superalloys

Abstract

For grinding of superalloys, Difficult to Grind (DTG) materials, superabrasive grinding wheels of cBN (cubic boron nitride) with vitrified bond are considered the first choice for light roughing and finishing due to their superior performance when compared to conventional grinding wheels. However, there are limitations on the use of cBN wheels due to the higher initial cost of the cutting tool and the need for dressing systems with rotary tools. Aiming at reducing operational costs, the use of conventional grinding wheels with ceramic grains and high retention binder and lower bond-abrasive ratio is becoming increasingly common. In this scenario of introduction of new abrasive tools, it is necessary to use tools to evaluate the comparative performance of grinding wheels, which can encompass different aspects of the grinding process under study and which includes technical requirements of the component to be ground, as well as indicators of sustainability of the process. Thus, the objective of this work is to propose an evaluate strategy of the performance of grinding wheels whose methodology of analysis encompasses, in a coordinated way, traditional evaluation parameters and sustainability criteria (economic, environmental, and social) and that can be applied, as a study of case, in the grinding of superalloys for engine components, with different degrees of grindability. A high-performance engineered conventional grinding wheel and a vitrified cBN wheel were comparatively evaluated. The proposed methodology included the determination of the characteristic curve of a grinding wheel, coordinated analysis of the output parameters of the grinding process and the introduction of sustainability indicators. The results show the proposed global strategy proved to be viable and effective in comparing different grinding wheel specifications by encompassing aspects of the economic, environmental, and social performance of the grinding process. As a conclusion, the feasibility of the high-performance conventional wheel in substitution of the cBN wheel was confirmed for the grinding of the tested superalloys.