Fractal Analysis Approach for Studying Pores in Cast Al Alloys

The conventional method of reducing porosity in cast products includes sequential solidification, addition of risers and modification of the speed of pouring of the molten metal which are all pre-casting methods.In this study post casting method of reducing effects of harmful pores and identifying the point of crack initiations for eventual failure in cast products have been developed for aluminum alloys tested.These new methods were applied to the micro structures of the cast aluminum alloys to effect pore shape change,reduction in percentage porosity and identification of the point of crack initiation.In addition,it has been established that for heat treated samples, through the resulting curves that there is a critical value of sphericity (i.e a minimum point)above which any increase in sphericity causes a corresponding increase in fractal Dimension.