The Effect of Seal Position on Stresses and Deformations in Dies for Semi-Continuous Hydrostatic Extrusion
Due to the cyclic nature of the process of semi-continuous hydrostatic extrusion, deformations arise particularly at the die throat affecting the final dimensions and causing localised indentations of the product.
In the present work, a finite element analysis of the die has been compared with a previous solution using the point matching technique. No satisfactory agreement was achieved. Results were also compared with the experimental work previously carried out and good agreement was obtained.
Experimental work carried out by the authors confirmed the effect of changing the seal position on the final dimensions and form of the product. The optimum seal position is the one which gives the minimum local indentation of the product at the die throat on cycling the pressure; this can be predicted from the theoretical analysis.
The analysis can also be used to predict the most highly stressed portion of the die and hence enable the maximum allowable cyclic pressure to be determined.
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