Glass Formability and Diffusion Mechanisms in Bulk Metallic Glasses and Supercooled Liquids

2005 ◽  
Author(s):  
Yue Wu
2007 ◽  
Vol 561-565 ◽  
pp. 1271-1274 ◽  
Author(s):  
Tohru Yamasaki ◽  
S. Maeda ◽  
Takeyuki Kikuchi ◽  
Takeshi Fukami ◽  
Yokoyama Yoshihiko ◽  
...  

Viscous flow behavior in supercooled liquid region of as-cast and pre-annealed Zr55Cu30Al10Ni5 bulk metallic glasses has been examined by using a penetration viscometer under high-speed heating rate of 20, 200 and 400 °C/min. Applied load for the cylindrical-shaped penetration indenter with a diameter of 1 mm was varied from 0.049 N to 0.294 N. Viscosity was quite independent of these applied loads. By pre-annealing the bulk metallic glasses at 400 °C, the density of the glasses increased, while the viscosity and the activation energy for viscous flow in their soopercooled liquid decreased with the pre-annealing treatments. Corresponding measurements of the differential thermal calorimetry (DSC) have been also done.


2010 ◽  
Vol 654-656 ◽  
pp. 1046-1049 ◽  
Author(s):  
Tohru Yamasaki ◽  
M. Yamada ◽  
T. Mori ◽  
Takeyuki Kikuchi ◽  
Yokoyama Yoshihiko ◽  
...  

Viscous flow behaviour of supercooled liquids and mechanical properties in Zr55+XCu30-XNi5Al10 (X=0, 5 and 10 at. %) and Zr65Cu18Ni7Al10 bulk metallic glasses (BMGs) have been examined. Viscosity has been measured by using a penetration viscometer at a high-speed heating rate of 400 K/min. With increasing Zr-content, Tg tended to decrease and Tx tended to increase, resulting Tx (=Tx-Tg) increaseing up to about 170 K under a heating rate of 400 K/min by the DSC analysis. The viscosity lowered about one order of magnitude, e.g., minimum value of the viscosity decreased from 3~4x106 Pa-s for the Zr55Cu30Ni5Al10 and Zr60Cu25Ni5Al10 BMGs down to 5~6x105 Pa-s for the Zr65Cu20Ni5Al10 and Zr65Cu18Ni7Al10 BMGs under the same heating condition. Compression tests were also carried out at a slow strain rate of about 1 x 10-4 s-1 at room temperature. With increasing Zr-content, the apparent yield stress was decreased but the total strain at fracture was increased significantly, suggesting that there is a strong relationship between viscosity and the mechanical properties in these BMGs.


2007 ◽  
pp. 1271-1274
Author(s):  
Tohru Yamasaki ◽  
S. Maeda ◽  
Takeyuki Kikuchi ◽  
Takeshi Fukami ◽  
Yoshihiko Yokoyama ◽  
...  

2010 ◽  
Vol 207 (12) ◽  
pp. 2693-2703 ◽  
Author(s):  
Ping Wen ◽  
Zuo Feng Zhao ◽  
Ming Xiang Pan ◽  
Wei Hua Wang

2003 ◽  
Vol 94 (5) ◽  
pp. 615-620 ◽  
Author(s):  
Mariana Calin ◽  
Jürgen Eckert ◽  
Ludwig Schultz

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