Fatigue Life Prediction of Counter Pressure Casting A356 Aluminum Alloy Based on Secondary Dendrite Arm Spacing
Due to the complex structure and non-uniform solidification conditions of counter pressure casting,the dis-tribution of secondary dendrite arm spacing in the castings exhibits apparently difference,which leads to different prop-erties at different areas.At present,finite element analysis in the product design stage uses uniform material fatigue model,resulting in deviation between simulation and test results.The secondary dendrite arm spacing measurement and material fatigue tests were carried out at different areas of counter pressure castings to evaluate the quantitative rela-tionship between fatigue life,stress and secondary dendrite arm spacing of alloy,and then the S-N curves correspond-ing to different secondary dendrite arm spacing were obtained.Experimental tests validate that the prediction results of the quantitative relationship are in good agreement with the experimental ones,and the maximum absolute value of the logarithm relative error of predicted fatigue life is below 2%.Meanwhile,crack initiation and propagation mechanism were expounded by scanning electron microscopy(SEM)observation.
Counter Pressure CastingA356 AlloySecondary Dendrite Arm SpacingFatigue Properties
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