한국소성가공학회:학술대회논문집 (Proceedings of the Korean Society for Technology of Plasticity Conference)
- 한국소성가공학회 2001년도 추계학술대회 논문집
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- Pages.228-232
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- 2001
항공기용 Al 합금 단조품의 특성 향상을 위한 단조 공정 설계
Forging Process Design to Improve the Properties of Al Alloy Forged Part for Aerospace
초록
Fatigue strength, electrical conductivity and stress-corrosion-cracking resistance are considered as important factors at aircraft Al alloys, therefore Al7050 alloy has been developed to improve such properties. However, hammer-forged Al7050 parts showed the undesirable structures such as severe local grain coarsening and inhomogeneous material flow, resulted in the degraded mechanical properties. In this paper, process conditions are investigated for elimination of the grain coarsening and improved material flow during forging process by both of experiments and FEM analysis. Particular interest has been given to understand role of preform shape on the grain coarsening behavior and magnitude of the hammer forging load The use of preform has been beneficial for reduction of the forging load and elimination of the grain coarsening. However, in the cases of as received bar and the round bar, which was machined to 2.5mm thickness in surface layer, some degree of local grain coarsening behavior has been observed. The optimized preform shape could be properly designed by applying the FEM simulation.
키워드