Observation of the Complex Local Crystallization Process in Ti-Zr-Cu-Pd Amorphous Ribbons and Bulk Metallic Glass

2013 ◽  
Vol 58 (2) ◽  
pp. 347-350 ◽  
Author(s):  
A. Sypień
Keyword(s):  
Metallic Glass ◽  
Metallic Glasses ◽  
Crystallization Process ◽  
Amorphous Matrix ◽  
Glass Forming Ability ◽  
Duplex Microstructure ◽  
Glass Forming ◽  
Amorphous Ribbons ◽  
Nanocrystalline Particles ◽  
High Resolution Tem

In recent years, bulk metallic glasses (BMGs) have attracted much attention, especially concerning the reasons for the high glass-forming ability. To understand properties and glass-forming ability of BMGs, it is important to investigate their atomic structure in details. The structure of the metallic glass, derived from diffraction studies, confines mainly to short-range-order atomic correlations, which are statistically averaged over the glassy specimens. In the present study, local structure of a BMG and ribbons was observed using a high-resolution TEM (TECNAI G2 FEG). The TEM images of the BMG before annealed in the temperature below the crystallization clearly reveal a duplex microstructure consisting of nanocrystalline particles about 5-10 nm in size distributed uniformly in the amorphous matrix. Due to the FFT research the crystalline phases may be indexed as the Cu8Zr3, Cu3Pd, CuTi2 and CuTiZr.

Effect of Fe on Crystallization Process of Zr-Co-Al-(Fe) Bulk Metallic Glasses

2013 ◽  
Vol 745-746 ◽  
pp. 734-739 ◽  
Author(s):  
J. Tan ◽  
Fu Sheng Pan ◽  
C.J. Li ◽  
J.F. Wang ◽  
J. Eckert
Keyword(s):  
Activation Energy ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Metallic Glasses ◽  
Crystallization Process ◽  
Glass Forming Ability ◽  
Partial Replacement ◽  
Heat Of Mixing ◽  
Glass Forming ◽  
Internal States

The change in the internal states of Zr56Co28Al16 bulk metallic glass (BMG) upon minor substitution of Co with Fe was investigated for alloys with different compositions of Zr56Co28-xAl16Fex (x = 0, 1 and 2, respectively). Results exhibited that the ductile Zr-Co-Al-Fe BMGs were obtained and showed better glass-forming ability (GFA) via a small amount of Co partial replacement by Fe. In addition, the addition of a small amount of Fe enhanced the crystallization process and reduced the activation energy. The micro-alloying with Fe reduced the heat of mixing, which made the rearrangement of atoms easier during the crystallization process.

Effect of Minor Si and Ag Additions on Glass-Forming Ability of Ti-Cu-Co-Zr-Sn-Be Bulk Metallic Glass

2011 ◽  
Vol 688 ◽  
pp. 400-406
Author(s):  
Xin Fang Zhang ◽  
Hong Xiang Li ◽  
Zhi Qiang Jiang ◽  
Seong Hoon Yi
Keyword(s):  
Metallic Glass ◽  
Metallic Glasses ◽  
Base Alloy ◽  
Maximum Size ◽  
Amorphous Structure ◽  
Glass Forming Ability ◽  
Copper Mold ◽  
Glass Forming ◽  
Splat Quenching ◽  
Ag Additions

Effect of Minor Si and Ag additions on glass-forming ability (GFA) of the base Ti44Cu38.9Co4Zr6Sn2Be5.1(at. %) alloy are studied. (Ti44Cu38.9Co4Zr6Sn2Be5.1)100-xRx(R = Si, Ag, x=0, 1, 2, 3 at. %) metallic glasses are formed by splat-quenching and copper mold suction casting. It is found that the minor Si and Ag additions enhance the glass-forming ability of Ti44Cu38.9Co4Zr6Sn2Be5.1greatly. The maximum size of fully amorphous structure is increased from 4 mm for base alloy to be larger than 6 mm for alloys containing 1-2 at. % Si/Ag, while Si/Ag more than 2 at. % additions decrease the GFA.

Co-Based Bulk Metallic Glasses with Good Soft-Magnetic Properties and High Strength

2017 ◽  
Vol 898 ◽  
pp. 703-708 ◽  
Author(s):  
Qi Kui Man ◽  
Ya Qiang Dong ◽  
Chun Tao Chang ◽  
Xin Min Wang ◽  
Run Wei Li
Keyword(s):  
Magnetic Properties ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Eutectic Point ◽  
Glass Forming Ability ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Glass Forming

The thermal stability, glass-forming ability, soft-magnetic properties and mechanical properties of Co46Fe19+xB22.5Si5.5Nb7–x (x=0–2) bulk metallic glasses were investigated. The 5.5 at% Nb addition was found to be effective in approaching alloy to a eutectic point, resulting in an increase in glass-forming ability. By copper mold casting, bulk metallic glass rods with diameters up to 5 mm were produced. Except for high glass-forming ability, the bulk metallic glasses also exhibit good soft-magnetic properties, i.e., low coercive force of 1.34–2.14 A/m, high effective permeability at 1 kHz of 2.26–3.06×104, and high fractures strength (σf) of 4010–4460 MPa. This Co-based bulk metallic glass system with high strengths and excellent soft-magnetic properties is promising for future applications as a new functional material.

Glass-Forming Ability and Mechanical Properties of Fe-Ni-Zr-Si-B Bulk Glassy Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 3405-3408
Author(s):  
K.A. Lee ◽  
J. Namkung ◽  
Moon Chul Kim
Keyword(s):  
Plastic Strain ◽  
Metallic Glass ◽  
Structural Relaxation ◽  
Amorphous Matrix ◽  
Icosahedral Phase ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
Glassy Alloys ◽  
Partial Crystallization ◽  
Crystallization Onset

The effects of structural relaxation and partial crystallization on the mechanical property of the Ti40Zr29Cu9Ni8Be14 bulk metallic glass (BMG) have been investigated. The atomic structure of the as-cast Ti40Zr29Cu9Ni8Be14 metallic glass transforms into a more relaxed state at the temperature region of 452 –585 K, below the crystallization onset temperature of 631 K. Stable icosahedral phase forms in the amorphous matrix by growth of the pre-existing nuclei in the amorphous matrix during first crystallization step. The compressive plastic strain of the as-cast Ti40Zr29Cu9Ni8Be14 BMG is 6.7 %, and decreases when the structural relaxation occurs. However, the plastic strain increases when a few nanometer size icosahedral phase particles form in the amorphous matrix by the partial crystallization treatment.

scholarly journals Effect of Hafnium and Zirconium to Glass Forming Ability, Thermal Stability, Plasticity Deformation and Crystallization of Ni-Free Pentabasic Ti-Based Bulk Metallic Glasses

2017 ◽  
Vol 62 (2) ◽  
pp. 1081-1087
Author(s):  
J.J. Oak ◽  
Y.H. Kim ◽  
K.C. Bae ◽  
Y.H. Park
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
Compressive Strength ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Metallic Glasses ◽  
Fracture Behavior ◽  
Glass Forming Ability ◽  
High Activation ◽  
Glass Forming

AbstractThe newly designed Ti-based bulk metallic glass (BMG) in which case of fracture behavior was observed 1990MPa to compressive strength with a wide plastic deformation around 7% after process of elastic deformation. This phenomenon can be compared with those of Ti-based alloys and other Ti-based BMGs and indicates high potential to be applied in use. It was evaluated the Ti-based BMG for thermal stability that the reduced glass parameters, ΔTx,Trgand γ, are 79K, 0.50 and 0.38, respectively. In addition, it reveals high activation energies for crystallization in which are estimated toEx1= 291.77 ±9.71 kJ/mol,Ex2= 588.77 ±28.88 kJ/mol andEx3= 330.26 ±3.61 kJ/mol on kissinger plotting in this study.

Room-Temperature Mechanical Properties and Glass Formation of Zr50Cu20Ni15Al(15-X)Tix (x=3, 5, 7) Bulk Metallic Glass Alloys

2011 ◽  
Vol 66-68 ◽  
pp. 741-746
Author(s):  
Jia Hua Zou ◽  
Zhi Chen Zhang ◽  
Shu Quan Sun
Keyword(s):  
Mechanical Properties ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Metallic Glasses ◽  
Glass Formation ◽  
Room Temperature ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
Ti Content ◽  
Ti Addition

In the present study, the Zr-Cu-Ni-Al based bulk metallic glasses with different Ti addition was successfully prepared by suction casting . It was found that the glass forming ability was improved with increasing of Ti content from 3 at.% to 7 at.%. However, with increasing of Ti content, the room-temperature plasticity decreased from 4.33% to 0.66 %.

Glass–Forming Ability of Fe60Co8Zr10Mo5W2B15 Alloy with Industrial-Pure Raw Materials

2010 ◽  
Vol 426-427 ◽  
pp. 621-623 ◽  
Author(s):  
H.X. Xiao
Keyword(s):  
Metallic Glass ◽  
Metallic Glasses ◽  
Raw Materials ◽  
Low Cost ◽  
Glassy State ◽  
Alloy System ◽  
Glass Forming Ability ◽  
Glass Forming ◽  
Quenching Process ◽  
Electromagnetic Mixing

Special remelting techincs including repeating the heating and quenching process for several times, electromagnetic mixing during the melting, increasing the superheating temperature, prolonging isothermal time can effectively decrease or remove the effect of impurity in raw materials on the glass-forming ability (GFA) of the alloy system. These technics were introduced to improve GFA of Fe60Co8Zr10Mo5W2B15 alloys (△Tx = 64 K, Trg = 0.61, Trg’= 0.59). Bulk metallic glasses of Fe60Co8Zr10Mo5W2B15 with the shape of rods (φ3×40) and plates (1×10×20) were casted into fully glassy state. It was proved the GFA of Fe60Co8Zr10Mo5W2B15 with industrial raw materials is very close to that with high purity raw materials. Fe60Co8Zr10Mo5W2B15 bulk metallic glass with industrial raw materials shows better potential appliance for their low cost.

Effect of Minor V Addition on Al88Y7Fe5 Amorphous Alloys

2013 ◽  
Vol 302 ◽  
pp. 76-81 ◽  
Author(s):  
H.W. Yang ◽  
M.J. Tan ◽  
R.D. Li ◽  
J.Q. Wang
Keyword(s):  
Mechanical Properties ◽  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Amorphous Ribbon ◽  
Glass Forming Ability ◽  
High Magnification ◽  
Vein Pattern ◽  
Glass Forming ◽  
Amorphous Ribbons ◽  
Smooth Region

The effect of the addition of 0.2-0.65 at% of V on the glass forming ability and mechanical properties of Al88Y7Fe5 alloy were investigated. The addition of V in this range had little effect on the glass forming ability of the alloy, but lowered the tensile strength of the amorphous ribbon. The fracture surface of Al88Y7Fe5 amorphous ribbons was typical vein pattern for ductile metallic glasses, however, that of the alloy with 0.5% V addition changed to two different regions, i.e., vein pattern region and smooth region. At high magnification, the smooth region was composed of nanometer sized corrugations, which is typical for brittle metallic glasses.

Enhancing bulk metallic glass formation in Ni–Nb–Sn-based alloys via substitutional alloying with Co and Hf

2008 ◽  
Vol 23 (3) ◽  
pp. 688-699 ◽  
Author(s):  
Li Zhang ◽  
Mu-Jin Zhuo ◽  
Jian Xu
Keyword(s):  
Metallic Glass ◽  
Ternary System ◽  
Metallic Glasses ◽  
Glass Formation ◽  
Composition Range ◽  
Glass Forming Ability ◽  
Partial Substitution ◽  
Wide Composition Range ◽  
Positive Effects ◽  
Glass Forming

Bulk metallic glasses have been formed over a fairly wide composition range (54–62 at.% Ni, 32–36 at.% Nb, and 3–11 at.% Sn) in the Ni–Nb–Sn ternary system. Partial substitution of Co for Ni and Hf for Nb improves the glass-forming ability, eventually leading to 4 mm glassy rods at the Ni56Co3Nb28Hf8Sn5 composition. The positive effects of these alloying elements have been explained based on a systematic monitoring of the amount and morphology of the competing crystalline phases as a function of the Co and Hf contents.

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