【作者】 王发东； 张曙光； 胡捷； 徐俊； 吴春京； 石力开；

【Author】 WANG Fa-dong, ZHANG Shu-guang, HU Jie, XU Jim, WU Chun-jing, SHI Li-kai (School of Materials Science and Technology, University of Science and Technology Beijing, Beijing 10083, China; National Engineering Research Center for Nonferrous Metals Composites, General Research Institute for Nonferrous Metals, Beijing 100088, China; School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200030, China)

【机构】 北京科技大学材料科学与工程学院； 上海交通大学材料科学与工程学院； 北京有色金属研究总院国家有色金属复合材料工程技术研究中心；

【摘要】 通过Gleeblel500热模拟试验,选择纯铁作为挤压包套材料,然后对非晶合金在温度为663 K、应变速率为8.9×10-1s-1的条件下进行静液挤压。研究结果表明:Zr基非晶合金产生了塑性变形,但没有发生均匀粘滞性流动,而是断裂成两段;样品断口上随机分布着充分发展与未充分发展的“脉纹”状切变带,断面上出现了类似流动熔体凝固后的特征结构;高应变速率变形条件使非晶合金产生的非均匀流变,以及静液挤压时纯铁先于非晶合金的流动变形是造成非晶合金断裂的主要原因。挤压态非晶合金的过冷温度区间减小,热稳定性有所降低。更多还原

【Abstract】 Through the uniaxial compressive deformation test, iron was selected as sheath materials for extrusion of bulk amorphousalloy because of their similar deformation behavior under the testing conditions. Then the bulk a-morphous alloy was processed by hydrostatic extrusion at 663 K and strain rate of 8. 9×10-1s-1. It is shown that the alloy has undergone plastic elongation, however, the alloy does not show uniform viscous flow behavior and fractured into two sections. The fracture surfaces are revealed randomly distributed well developed and partially developed veinal patterns, and a different pattern appear on the fracture surface, which is very similar to the flowing-liquid solidified immediately. The main reason of fracture of the alloy may be attributed to nonuniformly flow under the high strain rate and relative motion between the alloy and the iron when hydrostatic extrusion began. And it is found that heat stability turns down, because the supercooled region of the bulk amorphous alloy becomes narrow.更多还原