缩径区长度对粘性介质外压缩径成形的影响

粘性介质外压缩径采用半固态、可流动、高粘度和一定速率敏感性的高聚物作为缩径用传力介质,有效地解决了缩径成形过程的失稳起皱问题,提高了坯料的极限缩径量.本文针对不同缩径区长度对粘性介质外压缩径过程的影响问题,采用试验和有限元方法进行了分析,得到了不同缩径区长度条件下1Cr18Ni9Ti薄壁管的极限缩径量及应力与应变的分布规律.研究结果表明,缩径区长度对粘性介质外压缩径成形影响较大,缩径区长度越短,坯料的抗失稳起皱能力越强,极限缩径量越大.

Influence of necking length on viscous medium outer pressure necking forming

Viscous medium outer pressure necking uses semisolid, flowable, highly viscous and certain rate sensitivity super-polymer as pressure carrying medium which can solve wrinkling problem during necking forming effectively and increase necking limit of specimen. Experiment and finite element methods were adopted to analyze the problems of the influence of different necking length on the process in viscous medium outer pressure necking. The necking limit and distribution rule of stress and strain of 1Cr18Ni9Ti thin-wall tube under the conditions of different necking length were obtained. Results show that the influence of necking length on viscous medium outer pressure necking forming is biggish. The ability of specimen to resist buckling is high and necking limit is big with the short necking length.