Performance evaluation of cryogenic liquid nitrogen as a coolant in the grinding process

Abstract

The challenges facing machining industries today are high metal newlineremoval rate and better product quality. Grinding is vital to many newlinemanufacturing processes as it generates finer surfaces and closer dimensional newlinetolerances. The selection of the machining parameters is crucial for a better newlineperformance in the grinding process. The grits are continuously abraded, newlinefractured, and dislodged from the bond. New grits are exposed to combination newlineof cutting, plowing and rubbing which is changing continuously. The grinding newlineprocess generates large energy, and most of the energy is converted to heat. newlineThe intense heat affects the mechanical properties of the work material and newlinethe grits of the grinding wheel. The dullness of the grit affects the surface newlinequality, and increases the grinding forces. New grits are exposed to frequent newlinegrit breakages, and wear of the wheel increased rapidly. The problems with newlinethe conventional coolant are the flow of the material around the grit and newlinefailure of the lubrication at higher removal rates. All these lead to poor quality surfaces and failure of the components. newlineThe coolant which received the attention of researchers is liquid newlinenitrogen (LN2) used in cryogenic machining. The application of LN2 as newlinecoolant in the different manufacturing processes like turning, and milling has newlinedesired beneficial improvements in the generation of defect free surfaces, and newlinelower residual stresses due to effectiveness in control of grinding zone newlinetemperature. Cryogenic machining is an environmentally accepted clean newlinetechnology. In the present study, a cryogenic cooling system has been newlinedeveloped for supplying liquid nitrogen to the cutting zone of the work newlinematerial and the grinding wheel interface of the surface grinding process. newlineGrinding experiments were carried out with AISI 316 stainless steel, EN31 newlinesteel and AISI D3 steel, with Al2O3 (aluminum oxide) and sol-gel (SG) newlinealumina grinding wheel at different depth of cut-work speed combinations newlineunder dry, wet and cryogenic cooling conditions. newline