Influence of Y and Nb Addition on Crystallization Behavior and Mechanical Properties of Zr-Ni-Al-Cu-M Bulk Amorphous Alloys

2011 ◽  
Vol 326 ◽  
pp. 11-18 ◽  
Author(s):  
Muhammad Iqbal ◽  
Javed Iqbal Akhter
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Amorphous Alloys ◽  
Crystallization Behavior ◽  
Liquid Region ◽  
Mechanical And Thermal Properties ◽  
Bulk Amorphous Alloys ◽  
Wide Range ◽  
Stage Crystallization ◽  
Nb Addition

Bulk amorphous alloys are new class of materials with excellent mechanical and thermal properties. Bulk metallic glasses (BMGs) have wide range of application such as structural materials. Minor alloying additions play beneficial role in the production and properties of BMGs. The present study was conducted to investigate the effect of Y and Nb addition on activation energy, crystallization behavior, thermal and mechanical properties of Zr64.5Ni15.5Al11.5Cu8.5. Bulk amorphous ingots and sheets of three [Zr0.645Ni0.155Al0.115Cu0.085]100-xM2 (M = Y and Nb and x = 0, 2 at. %) alloys were produced by Cu mold casting technique. The alloys were characterized by XRD, DSC, SEM, FESEM and EDS. Activation energies were calculated. The alloy containing Y shows single stage crystallization while Nb addition shows double stage crystallization. The maximum activation energy calculated is 300 kJ/mol. Parameters describing thermal stability in these systems were determined from DSC data which improved as a result of these additives. Reduced glass transition temperature Trg and thermal parameters like g, d and b were improved by Y addition. The supercooled liquid region varies between 87-100 K. Hardness and elastic moduli were also improved. It was concluded that Y and Nb addition has beneficial effect on mechanical properties. Three phases NiZr2 and CuZr2 and Cu10Zr7 were identified by XRD and confirmed by EDS in the samples annealed at 823 K while the AlNiY ternary phase was detected in the alloy containing Y.

scholarly journals Relationship between the Stereocomplex Crystallization Behavior and Mechanical Properties of PLLA/PDLA Blends

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1851
Author(s):  
Hye-Seon Park ◽  
Chang-Kook Hong
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Crystallization Behavior ◽  
Mechanical Analysis ◽  
X Ray Diffraction ◽  
Nucleation Agent ◽  
Scanning Calorimetry ◽  
Nucleation Sites ◽  
Wide Range ◽  
Degree Of Crystallization

Poly (l-lactic acid) (PLLA) is a promising biomedical polymer material with a wide range of applications. The diverse enantiomeric forms of PLLA provide great opportunities for thermal and mechanical enhancement through stereocomplex formation. The addition of poly (d-lactic acid) (PDLA) as a nucleation agent and the formation of stereocomplex crystallization (SC) have been proven to be an effective method to improve the crystallization and mechanical properties of the PLLA. In this study, PLLA was blended with different amounts of PDLA through a melt blending process and their properties were calculated. The effect of the PDLA on the crystallization behavior, thermal, and mechanical properties of PLLA were investigated systematically by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), polarized optical microscopy (POM), dynamic mechanical analysis (DMA), and tensile test. Based on our findings, SC formed easily when PDLA content was increased, and acts as nucleation sites. Both SC and homo crystals (HC) were observed in the PLLA/PDLA blends. As the content of PDLA increased, the degree of crystallization increased, and the mechanical strength also increased.

scholarly journals Crystallization Behavior of Al70Fe12.5V12.5Nb5 Amorphous Alloy Formed by Mechanical Alloying

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 383 ◽  
Author(s):  
Xuan Liu ◽  
Xingfu Wang ◽  
Yongli Si ◽  
Xiaokang Zhong ◽  
Fusheng Han
Keyword(s):  
Amorphous Alloy ◽  
Mechanical Alloying ◽  
Amorphous Alloys ◽  
Crystallization Behavior ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Liquid Region ◽  
Application Field ◽  
Glass Forming

In this study, the formation and crystallization of the Al70Fe12.5V12.5Nb5 amorphous alloys has been investigated. The addition of Nb enhances the supercooled liquid region and glass forming ability of the Al-Fe-V amorphous alloys. The Al70Fe12.5V12.5Nb5 amorphous alloy exhibits two distinct crystallization steps and a large supercooled liquid region at more than 100 K. Kissinger and Ozawa analyses showed that the two activation energies for crystallization (Ex) were estimated to be 366.3 ± 23.9 and 380.5 ± 23.9 kJ/mol. Large supercooled liquid regions are expected to gain an application field of Al-based amorphous alloys.

Comparison of the Decomposition and Crystallization Behavior of Zr and Pd Based Bulk Amorphous Alloys

2000 ◽  
Vol 343-346 ◽  
pp. 179-184 ◽  
Author(s):  
Jörg F. Löffler ◽  
William L. Johnson ◽  
W. Wagner ◽  
P. Thiyagarajan
Keyword(s):  
Amorphous Alloys ◽  
Crystallization Behavior ◽  
Bulk Amorphous Alloys

Quaternary and Quinary Ni-based Amorphous Alloys in the Ni-Zr-Ti-X (X=Al, Si, P) and Ni-Zr-Ti-Si-Y (Y=Sn, Mo, Y) Systems

2000 ◽  
Vol 644 ◽  
Author(s):  
M.H. Lee ◽  
S. Yi ◽  
T.G. Park ◽  
W.T. Kim ◽  
D.H. Kim
Keyword(s):  
Amorphous Alloys ◽  
Alloy System ◽  
Continuous Heating ◽  
Liquid Region ◽  
Undercooled Liquid ◽  
Bulk Amorphous Alloys ◽  
Glass Forming ◽  
Structural Application ◽  
Crystallization Mode ◽  
Zr Alloy

AbstractNew Ni-based bulk amorphous alloys in the alloy system Ni-Zr-Ti-X (X=Al, Si, P) and Ni-Zr- Ti-Si-Y (Y=Sn, Mo, Y) were developed through systematic alloy design based upon the empirical rules for high glass forming ability (GFA). Additions of a small amount of Si and/or Sn to a ternary Ni-Ti-Zr alloy are very effective to increase GFA as well as the undercooled liquid region (ΔTX). Changes in crystallization mode during continuous heating of amorphous phase and lowered liquidus temperature by quaternary and quinary additions are associated with the enhanced GFA and the enlarged ΔTx. Development of new Ni-based amorphous alloys with high GFA and large ΔTx expands structural application of amorphous alloys.

Synthesis and mechanical properties of Zr-based bulk amorphous alloys

2008 ◽  
Vol 354 (28) ◽  
pp. 3291-3298 ◽  
Author(s):  
M. Iqbal ◽  
J.I. Akhter ◽  
H.F. Zhang ◽  
Z.Q. Hu
Keyword(s):  
Mechanical Properties ◽  
Amorphous Alloys ◽  
Bulk Amorphous Alloys

Mechanical Properties of La-based Bulk Amorphous Alloys and Composites

2002 ◽  
Vol 754 ◽  
Author(s):  
M.L. Lee ◽  
Y. Li ◽  
W.C. Carter
Keyword(s):  
Mechanical Properties ◽  
Fracture Energy ◽  
Amorphous Alloys ◽  
High Volume ◽  
Intermetallic Phases ◽  
Impact Fracture ◽  
Crystalline Phases ◽  
Bulk Amorphous Alloys ◽  
Glassy Metals ◽  
The Impact

ABSTRACTThe influence of different microstructures of La-based fully amorphous samples and its composites on the impact fracture energy were investigated and discussed. Results showed improvement in fracture energy of glassy metals with intermetallic phases, but deteriorated in the presence of dendrite phases and high volume % of crystalline phases.

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