BT16钛合金渗氢压缩试样中的剪切带

为了深入了解渗氢及变形速率对BT16钛合金冷镦性能的影响,采用光学显微镜(OM)和显微硬度的方法,研究了BT16钛合金渗氢压缩试样中的剪切带.结果表明:在300 mm/s的压缩速率下,中心区变形流线与剪切带保持平行;在75 mm/s的压缩速率下,剪切带中心区与剪切变形过渡区边界模糊,变形流线与剪切带呈一定的小角度.在300 mm/s的压缩速率下形成的剪切带中心区显微硬度值近似为常数,且低于基体硬度值,剪切带中心区与基体之间存在一个硬度值线性增加的过渡区.对剪切带形成过程进行了分析,提出了利用变形流线计算剪切带最大应变的方法.

Shear Band of Compression Sample of Alloy BT16 after Hydrogenation

To understand the effect of hydrogenation and deformation rate on the property of alloy BT16 for cold heading, the shear band of a compression sample of a hydrogenated alloy BT16 specimen is investigated by means of optical microscope (OM) and microhardness test. The results show that the deformed flow line is parallel to the shear band formed at a deformation rate of 300 mm/s. There is no clear boundary between the central zone and transition zone in the shear band, and there is a small angle between the deformed flow line and the shear band formed at the deformation rate of 75 mm/s. When the shear band is formed at the deforma-tion rate of 300 mm/s, the microhardness value is approximately constant in the central zone of the shear band, and it is lower than that in the matrix. There is a transition zone between the central zone of the shear band and the matrix, in which the microhardness value increases linearly with the test point moving from the central zone of the shear band to the matrix. The formation process of the shear band is analyzed and a calculating method of the shear band strain is proposed by means of the deformed flow line.