Experimental apparatus for Continuous-Bending-under-Tension and experiments on AA6022-T4
Experimental apparatus for Continuous-Bending-under-Tension and experiments on AA6022-T4
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连续拉伸弯曲实验装置及AA6022-T4实验
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发表时间：
2016
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通讯作者：
T. Roemer
中科院分区：
文献类型：
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作者：
T. Roemer
一种被称为拉伸下连续弯曲（CBT）的实验技术可以通过防止颈缩不稳定性的发生来产生超过标准拉伸试验两倍的伸长率。这是通过使用三个辊沿着材料的标距长度在张力上叠加塑性弯曲来实现的。当辊施加三点弯曲时，试样保持在张力下，同时循环地穿过标距长度。这使得试样仅在辊所经过的区域中发生塑性变形。详细介绍了这种独特的CBT机的各个子系统的设计。在轧制直接（RD）和横向（TD）的各种CBT实验的结果进行了探索CBT参数空间。使用CBT机器进行了另外两种类型的实验。在一个，中断的CBT实验进行了研究在CBT过程中的规范区域内的晶粒结构的发展。在另一个，摩擦测试被用来确定在CBT过程中AA 6022-T4与钢辊之间的摩擦系数。后者是作为一种通用的方法来测量板料和模具之间的摩擦系数。制造业将受益于对提高CBT过程潜在伸长率的机制的更强的基本理解。
An experimental technique called Continuous-Bending-under-Tension (CBT) can produce elongations over two times that of a standard tensile test by preventing the necking instability from occurring. This is achieved by superposing plastic bending on tension along the gauge length of the material using three rollers. The specimen is kept under tension as the rollers apply three-point bending while cyclically traversing the gauge length. This subjects the specimen to plastic deformation only in the region that is visited by the rollers. Details on the design of various subsystems of this unique CBT machine are presented. The results for a variety of CBT experiments in the rolling direct (RD) and transverse direction (TD) were conducted to explore the CBT parameter space. Two additional types of experiments were conducted using the CBT machine. In one, interrupted CBT experiments were conducted to study the development of the grain structure within the gauge region during the CBT process. In the other, friction tests were used to determine the coefficient of friction between AA6022-T4 and the steel rollers during the CBT process. The latter is proposed as a general method to measure the friction coefficient between a sheet and a die. The manufacturing industry will benefit from a stronger fundamental understanding of the mechanisms that improve the potential elongation for the CBT process.