Directional Solidification Microstructure Control of NiAl-1.5at%W Eutectic Alloy and Morphology of W Meso-nanowires

作者：Ren Haiguo^*; Wang Wenjia; Gao Jianjun; Yan Guangming; Zhao Zhilong

来源：Rare Metal Materials and Engineering, 2016, 45(1): 222-226.

• metallic meso-nanowires
• directional solidification
• eutectic alloy
• selective dissolution

Under a temperature gradient of 300 K/cm, NiAl-1.5at%W eutectic samples were directionally solidified at different drawing rates. The effect of the drawing rates on the spacing and the size of W fiber phases was analyzed. In addition, the NiAl matrix was selectively etched by a solution of HCl:H2O2 to prepare the tungsten fiber filaments with the equivalent diameter less than 500 nm. The results show that with the drawing rate increasing the roundness of W fiber phase cross-section increases, while the spacing as well as the equivalent diameter of W fiber phase both decreases, and the ratio between them is in the range of 6.12 to 7.54. The tungsten fibers obtained by selective dissolution have the diversiform three-dimensional morphologies, such as the thin strip, pearl string and lapping state, and it is found that those shapes are related to the drawing rate.

• 出版日期2016-1
• 单位西北工业大学