Research on Oxide Film Mechanical Properties of ELID Grinding Wheel Surface by Nanoindentation

Oxide film on grinding wheel plays a significant role both in guaranteeing non-linear electrolysis of ELID (electrolytic in process dressing) grinding and improving the grinding surface quality. The nanoindentation technique is utilized to study the hardness, elastic modulus and stiffness of the oxide film. The study indicates that the hardness of the oxide film is about 210Mpa, 1/4-1/3 of the matrix hardness , which enables the oxide film to effectively separate the matrix and workpiece, thus preventing the matrix to scratch the grinding surface; And the elastic modulus of the oxide film is approximately 30-50Gpa, 1/6-1/3 of the matrix elastic modulus, therefore the elastic deformation occurs more easily, which is beneficial for the concertedness and equal height of grinding grains; The stiffness of the oxide film is around 15μN/nm, and the value relates to the grinding parameters due to the dynamic update of the oxide film. When implementing the precision grinding, the elastic deformation of oxide film reduces the exposure and grinding depth of the grinding grains, accordingly, ameliorating the grinding surface quality.