Severe plastic deformation by linear flow splitting
Severe plastic deformation by linear flow splitting
复制标题
DOI：
10.1002/mawe.200700210
复制
发表时间：
2007-10
影响因子：
1.1
通讯作者：
C. Müller;T. Bohn;E. Bruder;T. Bruder;V. Landersheim;C. E. Dsoki;P. Groche;D. Veleva
中科院分区：
文献类型：
--
作者：
C. Müller;T. Bohn;E. Bruder;T. Bruder;V. Landersheim;C. E. Dsoki;P. Groche;D. Veleva
采用新的线性流分岔成形工艺，使不需要复合材料的板料生产分岔型材成为可能。这种结构的连续生产是在改进的滚压成型机中逐步进行的。在生产这些复杂零件的过程中，由于冷成形，材料性能发生了与工艺相关的变化。因此，加工部件均质性的假设是无效的，只有考虑材料性能的变化才能对结构耐久性进行可靠的分析。对线性流动劈裂剖面的研究表明，剖面截面上的微观结构和性能有很大的梯度。在低塑化区，变形程度和流动应力可以通过显微组织和硬度测量来确定。在严重变形的区域，如上法兰表面，这种测定是值得怀疑的。因此，采用电子背散射衍射方法来研究在剧烈塑性变形过程中是否发生了超细晶结构。因此，本文的目的是对线性流分裂过程进行数值分析，分岔剖面的金相特征以及考虑到所获得的见解的结构耐久性的数值评估。
Due to the new linear flow splitting forming process the production of bifurcated profiles from sheet metal without lamination of material becomes feasible. The continuous production of such structures takes place incrementally in a modified roll forming machine. By producing those complex parts process‐related changes in the material properties occur as a result of the cold forming. Thus, the assumption of homogeneous properties in the processed part is not valid and a reliable analysis of structural durability is only possible by considering changes in material properties. Investigations on linear flow split profiles show large gradients in the microstructure and properties over the profile cross section. In the areas of low plastification the degree of deformation and the flow stress can be determined by microstructure and hardness measurements. In the severely deformed areas, like the upper flange surface, this determination becomes doubtable. Therefore the electron backscattered diffraction method was used to investigate, if an ultrafine‐grained structure is occurring as it evolves in the processes of severe plastic deformation. Thus, the aim of this paper is the numerical analysis of the linear flow splitting process, the metallographic characterisation of bifurcated profiles and the numerical evaluation of the structural durability with consideration of the gained insights.