Bulk Scandium-based Metallic Glasses

2005 ◽  
Vol 20 (9) ◽  
pp. 2243-2247 ◽  
Author(s):  
X.K. Xi ◽  
S. Li ◽  
R.J. Wang ◽  
D.Q. Zhao ◽  
M.X. Pan ◽  
...  
Keyword(s):  
Glass Transition ◽  
Rare Earth ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glasses ◽  
Elastic Moduli ◽  
Supercooled Liquid ◽  
The Novel ◽  
Casting Method ◽  
Mold Casting

The novel rare-earth scandium-based bulk metallic glasses (BMGs) are obtained by the copper mold casting method. Compared with other rare-earth BMGs reported so far, the Sc-based BMGs exhibit the highest elastic moduli (e.g., Young’s modulus, E = 85 GPa; bulk modulus, B = 77.5 GPa), glass transition temperature (Tg = 662 K), and crystallization temperature (Tx = 760 K) combined with a large region of supercooled liquid (ΔT = 98 K). A good correlation between glass transition temperature and elastic moduli is found in a variety of rare-earth-based BMGs.

Fe-based bulk metallic glasses with diameter thickness larger than one centimeter

2004 ◽  
Vol 19 (5) ◽  
pp. 1320-1323 ◽  
Author(s):  
V. Ponnambalam ◽  
S. Joseph Poon ◽  
Gary J. Shiflet
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glasses ◽  
Crystalline Phase ◽  
Elastic Moduli ◽  
Bulk Metallic Glasses ◽  
Maximum Diameter ◽  
Fluxing Agent

Fe–Cr–Mo–(Y,Ln)–C–B bulk metallic glasses (Ln are lanthanides) with maximum diameter thicknesses reaching 12 mm have been obtained by casting. The high glass formability is attained despite a low reduced glass transition temperature of 0.58. The inclusion of Y/Ln is motivated by the idea that elements with large atomic sizes can destabilize the competing crystalline phase, enabling the amorphous phase to be formed. It is found that the role of Y/Ln as a fluxing agent is relatively small in terms of glass formability enhancement. The obtained bulk metallic glasses are non-ferromagnetic and exhibit high elastic moduli of approximately 180–200 GPa and microhardness of approximately 13 GPa.

Preparation and Mechanical Properties of Hafnium-based Bulk Metallic Glasses

2000 ◽  
Vol 644 ◽  
Author(s):  
Xiaofeng Gu ◽  
Li-qian Xing ◽  
T. C. Hufnagel
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Strain Rates ◽  
Casting Method ◽  
Glass Forming ◽  
Arc Melting ◽  
Potential Use

AbstractWe have prepared bulk metallic glasses of composition (HfxZr1-x)52.5Cu17.9Ni14.6Al10Ti5 (with x=0-1) by an arc melting/suction casting method. The density of these alloys increases by nearly 67% with increasing Hf content, which is advantageous for their potential use as kinetic energy armor-piercing projectile materials. The glass transition temperature and the melting temperature increase linearly with increasing Hf content. The reduced glass transition temperature (Tg/Tm) decreases from 0.64 (x=0) to 0.62 (x=1), indicating reduced glass-forming ability for the Hf- based alloy. The fracture strength in uniaxial compression at quasi-static strain rates also increases with increasing Hf content, reaching ∼ 2.2 GPa for Hf52.5Cu17.9Ni14.6Al10Ti5.

scholarly journals Effects of Annealing on Enthalpy Recovery and Nanomechanical Behaviors of a La-Based Bulk Metallic Glass

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 579
Author(s):  
Ting Shi ◽  
Lanping Huang ◽  
Song Li
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Structural Relaxation ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Nanoindentation Measurement

Structural relaxation and nanomechanical behaviors of La65Al14Ni5Co5Cu9.2Ag1.8 bulk metallic glass (BMG) with a low glass transition temperature during annealing have been investigated by calorimetry and nanoindentation measurement. The enthalpy release of this metallic glass is deduced by annealing near glass transition. When annealed below glass transition temperature for 5 min, the recovered enthalpy increases with annealing temperature and reaches the maximum value at 403 K. After annealed in supercooled liquid region, the recovered enthalpy obviously decreases. For a given annealing at 393 K, the relaxation behaviors of La-based BMG can be well described by the Kohlrausch-Williams-Watts (KWW) function. The hardness, Young’s modulus, and serrated flow are sensitive to structural relaxation of this metallic glass, which can be well explained by the theory of solid-like region and liquid-like region. The decrease of ductility and the enhancement of homogeneity can be ascribed to the transformation from liquid-like region into solid-like region and the reduction of the shear transition zone (STZ).

Sign in / Sign up

Export Citation Format

Share Document