高应变速率压缩变形行为
(北京有色金属研究总院 复合材料中心， 北京 100088)
摘 要: 利用Gleeble1500热模拟机研究了Zr41.2Ti13.8Cu12.5Ni10Be22.5非晶合金在过冷液相区内633、 653和673 K，应变速率分别为2×10-2 s-1和2 ×10-1 s-1条件下的单向压缩变形行为。结果表明： 在673 K时两种应变速率下， 该合金都具有很好的塑性， 尤其在2×10-2 s-1时流变应力只有74 MPa，非常适于进行超塑性加工。 对非晶合金的断口进行了观察， 得到柱状非晶合金压缩变形时外观和断口形貌随着变形条件的变化规律。 采用自由体积模型对非晶合金的形变和断裂的微观机制进行了分析。
关键字: 锆基块体非晶合金; 过冷液相区; 变形; 断裂; 超塑性
（National Engineering Research Center for Nonferrous Metals Composites,
General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract: The uniaxial compressive deformation behavior of Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk amorphous alloy in the supercooled liquid region was studied at 633, 653 and 673 K, and high strain rate of 2×10-2 and 2×10-1 s-1. The result shows that the flow stress and the strain of the alloy strongly depend on the deformation temperature and strain rate. At 673 K, the alloy exhibits good ductility at both strain rates, and particularly at 2×10-2 s-1 its flow stress is only 74 MPa and the alloy is very suitable for superplastic forming. The fracture morphologies of the tested samples were observed by scanning electron microscopy, and the variation of the morphologies of the cylindrical specimens outlines and fracture surfaces with the processing conditions was summarized. The mechanism of the deformation and fracture of the alloy was analyzed by using the free volume model.
Key words: Zr-based bulk amorphous alloy; supercooled liquid region; deformation; fracture; superplasticity
