Study On The Surface Pore Structure Of Wood Ceramic And Its Effects On Friction Performance

The friction between mechanical parts during the process of mechanical transmission will affect the use performance of system and curtail the service life of parts. As a new kind of environmental protection material, wood ceramic material has better lubrication performance and it’s the ideal material to instead of traditional material manufacturing metal parts because of lubricating medium stored in surface tiny pores. The pore characteristics of material surface have significant effects on the friction performance. The pore structure of wood ceramic surface is complex, and surface pore characteristics of materials have significant effects on the friction lubrication performance. Therefore, to establish the unified representation standard for surface pore structure of wood ceramics and to study the influences of pore structure on friction lubricating performance will show important theoretical and practical significance.Taking surface pores of wood ceramics as the research object, study on digital image processing application of wood ceramics surface pore and fractal characterization method of surface pores are carried out. The model used for the analysis of friction performance of wood ceramics based on principle of the micro-cavity is built and the influences of surface pore characteristics on friction performance are studied.Firstly, based on image recognition principle, the SEM image of wood ceramics is enhancement processed by using wavelet analysis and histogram equalization methods, and the clearness image of pore structure is obtained. The contour curves of wood ceramic surface pores are extracted after binarization processing of wood ceramic clearness image by using MATLAB, and the areas and perimeters of wood ceramic surface pores are measured.Then, study on wood ceramic surface pore size distribution and the fractal dimension of the characterization is carried out by box-counting method. The SEM images of wood ceramics samples with different content of phenolic resin was grid processed, and the box number of average pores area and the box number of average pore perimeter were obtained by mathematical statistics. The influences of the content of phenolic resin on the change trends of the box number of average pores area, the box number of average pore perimeter and fractal dimension Dowere studied. The results show that:when the content of phenolic resin in50%～70%range, with the increase of phenolic resin content, the box number of average pores area, the box number of average pore perimeter increase, and the fractal dimension Dodeclines. Experiments prove that the complexity of wood ceramic surface pore boundary reduces with the increase of phenolic resin content.Finally, link the characteristics of wood ceramic pore structure to friction performance through building the friction system model which reflects the characteristics of the wood ceramic pore structure based on principle of micro-cavity. Results show that the main factors affect the wood ceramic friction performance include fractal dimension, pore area, pore size and pore depth, and with the increase of fractal dimension, the matching degree between tongues and grooves of surfaces get worse, the friction coefficient decline.