Composite Characterization Of Engineering Ceramics Ground Surface Topogarphy

Engineering ceramics surface is easy to form cracks, collapses, and other features during the machining process, which may rarely appear in the metal surface. Traditional methods of roughness characterization can not properly reflect the characteristics of engineering ceramics surface topography. In order to characterize the engineering ceramics ground surface more reasonably, it is necessary to explore new methods of characterization. And this research has important significance both in theory and in engineering technology.Based on the traditional characterization methods of surface topography, composite methods are introduced to characterize engineering ceramics ground surface in this paper. The main contents include:fractal method and wavelet method are used to describe the global and local characteristics of engineering ceramics ground surface, respectively; spectrum analysis is used to study frequency components and periodicity of original profile; material ratio curve of the profile and fractal method are used to characterize surface function. In order to improve the efficiency, analysis methods mentioned above are integrated into a surface measurement and analysis system. The complexity of the surface detection is reduced.From the results of analysis, the following conclusions can be drawn:(1) This article compares various methods to calculate profile dimension. By comparison, the variation method is suitable for extracting fractal dimension of engineering ceramics ground surface. The precision of variation method is further improved by modifying the error. Based on the analysis, we can draw a conclusion that the modified variation method is a reliable method for calculation of the fractal dimension, and can be used for fractal analysis of the engineering ceramics ground surface.(2) There is no one to one correspondence between arithmetical mean deviation of the assessed profile Ra and fractal dimension D. The fractal dimension of surfaces with the same material and Ra value may be significantly different. Fractal dimension is more stable than surface roughness Ra value for the same surface.(3) In general, the size order of mean fractal dimension is steel, zirconia, silicon nitride and alumina. It is the same as the order of fracture toughness of four materials.(4) The deep wave trough of engineering ceramics surface can well reflect the differences between metal and engineering ceramics surfaces. In order to quantitatively describe this characteristic, a concept called topography damage ratio is introduced in this paper.