Grain Boundary And Grain Boundary Node Fractal Dimensions Of Asymmetrical Rolled Pb-Ca-Sn-Al Alloy

Lead alloys,as the material of the grid of lead-acid battery,its corrosion resistance is the key point determining the working life of lead-acid battery.The distribution and kind of grain boundaries and grain boundary nodes(GBN)are the important factors which significantly influence the corrosion resistance of lead alloys.So,how to describe the distribution and kind of grain boundaries and GBNs is of great significance for material research.In order to research whether the fractal can be adopted to describe the distribution of GBN,the ferrite metallography figures of cold rolled low carbon steel sheet standard samples were used as research object.The caculation programs were compiled based on the box-counting fractal dimension(BFD)theory on the matalb software to explore whether the FD of the standard samples GBN exists or not.A new principle to ascertain the size of effective boxes was proposed aimed at the defect of the most BFD in caculating the FD of grain and grain boudrey nowadays.The grain and grain boundary BFDs of different sizes and ductility factors standard samples were caculated according to the new principle.The single factorexperiments of Pb-Ca-Sn-Al alloy were designed to caculate the grain and grain boundary FD of the alloy under different experiment paramaters(reduction rates,different spped rates,annealing temperatures,annealing time,tensions).Besides,the multifractal spectrums of Pb-Ca-Sn-Al alloy were also reseached to remedy the limitation of the sinple fractal.The results ensured the exisetence of GBN FD of the standard samples.The grain size and the the ductility factor have different influence on the FD of the grain,grain boundary and GBNs of standard samples.The FD of Pb-Ca-Sn-Al alloy GBN also exsited and had the same variation tendency with the FD of grain boundary under different experiment paramaters.There is same rules in the simple fractal and multifractal spectrums under the same experiment parameters.The FDof GBN exist.A new principle to ascertain the size of effective boxes is effective to calculate the FD of grain and grain boundary.There is a kind of relationship among the FD of grain,grain boundary and GBN.The simple fractal and multifractal spectrum can be both used to describe the microstructure,despite of from the different aspects.