Determination of Initial Billet Shape to improve Dimension Accuracy in Backdward Extruded Cups

후방압출공정에서 치수정밀도 향상을 위한 초기소재형상 결정

In general, cylinderical types of billet are use in the backward extrusion. It is difficult to obtain homogenious wall thickness by the backward extrusion using these. It is gradually increased that improving the accuracyand reducing the post machining of the final products. In manufacturing cup shaped parts by backward extrusion, it is very important to design optimal initial billet or preform. These can improve the accuracy of final products and remove the post machining processes. In this study, the influence of final parts geometry by the shape of initial billet as non machined types are discussed.