Plastic Deformation-Induced Nanocrystalline Aluminum in Al-Based Amorphous Alloys

1993 ◽  
Vol 321 ◽  
Author(s):  
H. Chen ◽  
Y. He ◽  
G. J. Shiflet ◽  
S. J. Poon
Keyword(s):  
Plastic Deformation ◽  
Amorphous Alloy ◽  
Shear Band ◽  
Thin Layer ◽  
Ball Milling ◽  
Direct Observation ◽  
Amorphous Alloys ◽  
Shear Bands ◽  
Amorphous Ribbons ◽  
Nanocrystalline Aluminum

ABSTRACTWe report the first direct observation of crystallization induced in the slipped planes of aluminum based amorphous alloys by bending the amorphous ribbons. Nanometer-sized crystalline precipitates are found exclusively within a thin layer (shear band) in the slipped planes extending across the deformed amorphous alloy ribbons. It is also found that the nanocrystalline aluminum can be produced by ball-Milling. It is likely that local atomic rearrangements within the shear bands create the nanocrystals which appear after plastic deformation.

Effect of Structure Relaxation on the Plastic Deformation Behaviour in a Zr-Based BMG under Indenter

2009 ◽  
Vol 618-619 ◽  
pp. 437-441
Author(s):  
Hao Wen Xie ◽  
Peter D. Hodgson ◽  
Cui E Wen
Keyword(s):  
Plastic Deformation ◽  
Shear Band ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Free Volume ◽  
Cast Alloy ◽  
Deformation Behaviour ◽  
Shear Bands ◽  
Structure Relaxation ◽  
Effect Of Structure

Vickers and nano indentations were performed on a structurally relaxed Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass (BMG), and the evolution of the shear bands in the relaxed BMG was investigated and compared to that in the as-cast alloy. Results indicate that the plastic deformation in the BMG with structure relaxation is accommodated by the semicircular (primary) and radial (secondary) as well as tertiary shear bands. Quantitatively, the shear band density in the relaxed alloy was much lower than that in the as-cast alloy. The annihilation of free volume caused by the annealing was responsible for the embrittlement of the sample with structure relaxation.

Dynamic indentation response of ZrHf-based bulk metallic glasses

2007 ◽  
Vol 22 (2) ◽  
pp. 478-485 ◽  
Author(s):  
Ghatu Subhash ◽  
Hongwen Zhang
Keyword(s):  
Shear Band ◽  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Shear Bands ◽  
Indentation Hardness ◽  
Strain Rates ◽  
Dynamic Indentation ◽  
Confinement Pressure ◽  
Static Indentation ◽  
Deformation Features

Static and dynamic Vickers indentations were performed on ZrHf-based bulk amorphous alloys. A decrease in indentation hardness was observed at higher strain rates compared with static indentation hardness. For equivalent loads, dynamic indentations produced more severe deformation features on the loading surface than static indentations. Using bonded interface technique, the induced shear band patterns beneath the indentations were studied. In static indentations, the majority of the deformation was primarily accommodated by closely spaced semicircular shear bands surrounding the indentation. In dynamic indentations two sets of widely spaced semicircular shear bands with two different curvatures were observed. The observed shear band patterns and softening in hardness were rationalized based on the variations in the confinement pressure, strain rate, and temperature within the indentation region during dynamic indentations. It is also proposed that free volume migration and formation of nano-voids leading to cracking are favored due to adiabatic heating and consequently cause the observed softening at high strain rates.

scholarly journals Effect of Niobium and Yttrium Modified Ti-Based Bulk Amorphous Alloy on Correlation of Plastic Deformation Energy and Ductility

2019 ◽  
Author(s):  
Shengfeng Shan ◽  
Bing Zhang ◽  
Yuanzhi Jia ◽  
Mingzhen Ma
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
Amorphous Alloys ◽  
Shear Bands ◽  
Deformation Energy ◽  
Bulk Amorphous Alloy ◽  
High Plasticity ◽  
Band Formation ◽  
Bulk Amorphous Alloys ◽  
Uniaxial Compressive Test

A series of Ti40Zr25Cu9Ni8Be18)100-xTMx (x = 0, 1, 2, 3, 4 at.%, TM = Nb, Y) Bulk amorphous alloys were designed and prepared using the copper mold casting method. The microstructures, glass forming ability and mechanical properties of the alloys were investigated by means of X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning colorimetry (DSC), depth-sensitive nanoindentation and uniaxial compressive test. The Bulk amorphous alloys with different ductility were investigated by measuring their plastic deformation energy (PDE) of the first pop-in events during loading. The relationships between the PDE value, shear band formation and ductility in Bulk amorphous alloys have been investigated. The results show that the PDE value decreases by the Nb addition and promotes the generation of multiple shear bands easily, which increase the fracture strength and plasticity significantly. Substituting Nb with Y has exactly the reverse effect. A useful rule for preparing of Bulk amorphous alloys with high plasticity is herein proposed, whereby the chemical composition of the Bulk amorphous alloys can be tailored to possess a lower PDE value.

Shear Band Feature in Two Bulk Metallic Glasses with Different Inherent Plasticity

2013 ◽  
Vol 703 ◽  
pp. 20-23
Author(s):  
Jian Sheng Gu ◽  
Hui Feng Bo ◽  
Hong Li ◽  
Zhan Xin Zhang
Keyword(s):  
Plastic Deformation ◽  
Shear Band ◽  
Temperature Rise ◽  
Metallic Glasses ◽  
Shear Banding ◽  
Shear Bands ◽  
Significant Difference ◽  
Coating Method ◽  
Deformation Ability

Shear banding characterization of Zr64.13Cu15.75Ni10.12Al10 and Zr65Cu15Ni10Al10 BMGs was studied by using Rockwell indention method. The significant difference in plastic deformation ability can be ascribed to different shear banding features. Meanwhile, by using the fusible coating method, thermal effect on shear bands was investigated. We did not see apparently temperature rise in shear bands of these two BMGs through Rockwell indentation.

scholarly journals Effect of Ni Addition on Catalytic Performance of Fe87Si5B2P3Nb2Cu1 Amorphous Alloys for Degrading Methylene Blue Dyes

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 341
Author(s):  
Jinfang Shi ◽  
Bingying Ni ◽  
Jingjing Zhang ◽  
Chen Wu ◽  
Daowen Cheng ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Amorphous Alloy ◽  
Ball Milling ◽  
Amorphous Alloys ◽  
Near Infrared ◽  
Amorphous Powder ◽  
Catalytic Performance ◽  
Wastewater Remediation ◽  
Ni Addition ◽  
Infrared Spectrophotometer

Fe-based amorphous alloys have shown great potential in degrading azo dyes and other organic pollutants. It has been widely investigated as a kind of environmentally friendly material for wastewater remediation. In this paper, we studied the effect of Ni addition on the catalytic performance of Fe87Si5B2P3Nb2Cu1 amorphous alloy for degradation of methylene blue dyes and analyzed the reaction mechanism. (Fe87Si5B2P3Nb2Cu1)86Ni14 amorphous powder with desirable performance was produced by specific ball milling durations. Characterization of the Fe87Si5B2P3Nb2Cu1 and (Fe87Si5B2P3Nb2Cu1)86Ni14 amorphous alloys prepared by ball milling was performed by XRD and SEM. Fe87Si5B2P3Nb2Cu1 and (Fe87Si5B2P3Nb2Cu1)86Ni14 amorphous alloys were used as catalysts to catalyze the degradation of methylene blue dyes, which were detected by UV-VIS near-infrared spectrophotometer. By a series of comparative experiments, it was found that a catalyst dosage of 0.2 g and a reaction temperature of 80 °C were conditions that produced the best catalytic effect. The degradation rate of (Fe87Si5B2P3Nb2Cu1)86Ni14 amorphous alloy to methylene blue dyes prepared by ball milling increased from 67.76% to 99.99% compared with the Fe87Si5B2P3Nb2Cu1 amorphous alloy under the same conditions.

Thermal Stability and Mechanical Properties of Hydrogenated Zr-Ni-Nb-Co Amorphous Alloy

2005 ◽  
Vol 486-487 ◽  
pp. 497-500 ◽  
Author(s):  
S. Jayalakshmi ◽  
Eric Fleury ◽  
Yu Chan Kim ◽  
Ki Bae Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Amorphous Alloy ◽  
Fracture Strength ◽  
Amorphous Alloys ◽  
Electrochemical Method ◽  
Amorphous Ribbons ◽  
Charging Time ◽  
Thermal Stability Of ◽  
A Current

Zr50Ni27Nb18Co5 amorphous ribbons were hydrogenated using an electrochemical method. Under a current density of 30 mA/cm2, the thermal stability of the amorphous phase was found to increase with the charging time. Hardness and fracture strength were found to be independent of charging time, indicating that the Zr-Ni-Nb-Co amorphous alloys preserved its mechanical integrity.

Severe Plastic Deformation of Amorphous Alloys

2008 ◽  
Vol 584-586 ◽  
pp. 227-230 ◽  
Author(s):  
Alex M. Glezer ◽  
Sergey V. Dobatkin ◽  
Margarita R. Plotnikova ◽  
Anna V. Shalimova
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Amorphous Alloy ◽  
Severe Plastic Deformation ◽  
Physical Properties ◽  
Plastic Flow ◽  
Low Temperatures ◽  
Amorphous Alloys ◽  
Thermally Activated ◽  
Different Temperatures

The structure and mechanical properties of amorphous alloy Ni44Fe29Co15Si2B10 after severe plastic deformation (SPD) in Bridgman chamber at the different temperatures (77 and 298 K) have been studied. It is shown that the early stages of the SPD of amorphous alloy cause a noticeable decrease in microhardness HV and significant changes in the physical properties. With increasing the value of SPD the transition from inhomogeneous to homogeneous (or to qualitatively different) mode of plastic flow is observed, which is accompanied by the effects of homogeneous nanocrystallization. The nanoparticle size does not exceed 10 nm. It is established that the thermally activated nanocrystallization processes can occur at very low temperatures (77 K).

Characterization of Shear Bands in Zr64.13Cu15.75Ni10.12Al10 and Zr65Cu15Ni10Al10 BMGs

2013 ◽  
Vol 703 ◽  
pp. 24-28
Author(s):  
Jian Sheng Gu ◽  
Hui Feng Bo ◽  
Hong Li ◽  
Zhan Xin Zhang
Keyword(s):  
Plastic Deformation ◽  
Shear Band ◽  
Shear Banding ◽  
Shear Bands ◽  
Band Pattern ◽  
Significant Difference ◽  
Deformation Ability

Shear banding characterization of Zr64.13Cu15.75Ni10.12Al10and Zr65Cu15Ni10Al10BMGs was studied by using Rockwell indention method. Well-developed shear band pattern can be found for both BMGs after indentation. The significant difference in plastic deformation ability can be ascribed to different shear banding features.

scholarly journals Microstructure and Mechanical Properties of Cu-Ni-Zr-Ti Bulk Metallic Glass Composites by Spark Plasma Sintering

2021 ◽  
Vol 59 (5) ◽  
pp. 281-288
Author(s):  
Da Woon Shin ◽  
Hong Min ◽  
Jin Kyu Lee
Keyword(s):  
Plastic Deformation ◽  
Shear Band ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Glass Matrix ◽  
Shear Bands ◽  
Glass Composites ◽  
Bulk Metallic Glass Composites ◽  
Plasma Sintering ◽  
Spark Plasma

In the present study, Cu54Ni6Zr22Ti18 bulk metallic glass composites were developed by spark plasma sintering(SPS) using gas atomized Cu54Ni6Zr22Ti18 metallic glass powders and Ta powders. Metallic glass composites with Ta phase were fabricated by SPS. The successful consolidation of Cu54Ni6Zr22Ti18 metallic glass matrix composites with the Ta phase was achieved through the strong bonding due to the plastic deformation of the Ta powder and the super-plastic behavior of the metallic glass powder in the supercooled liquid state during SPS. The deformed Ta phases were well distributed in the Cu54Ni6Zr22Ti18 metallic glass matrix. The compressive fracture strength and total strain were 1770 Mpa and 10.2%, respectively, for the Cu54Ni6Zr22Ti18 bulk metallic glass composite with 40 wt% Ta phases. The uniformly dispersed deformed Ta phase in the Cu54Ni6Zr22Ti18 metallic glass matrix effectively impedes the propagation of the first shear band and generates a second shear band, causing a crossing of the shear bands, resulting in an improvement in plastic strain. This increase in plastic deformation is related to the fact that the deformed Ta phase, uniformly distributed in the Cu54Ni6Zr22Ti18 metallic glass matrix, acts as a source of shear bands and at the same time effectively suppresses the movement of the shear bands, dispersing the stress and causing wide plastic deformation.

Influence of Strain Rate on Shear Localization during Deformation and Fracture of 5754 and 5182 Aluminium Alloy

2006 ◽  
Vol 519-521 ◽  
pp. 1047-1052 ◽  
Author(s):  
Mohammad Jaffar Hadianfard ◽  
Michael J. Worswick
Keyword(s):  
Plastic Deformation ◽  
Shear Band ◽  
Strain Rate ◽  
Shear Bands ◽  
Tensile Tests ◽  
Material Behavior ◽  
Damage Development ◽  
Band Formation ◽  
Deformation And Fracture ◽  
Localized Plastic Deformation

The effect of strain rate in the range of 10-4 to 10-1 s-1 on localization of deformation and fracture behavior of 5754 and 5182 aluminum alloys is investigated. For this study, tensile tests, interrupted tensile tests, shear band decoration, fractography and image analysis has been used. This investigation is based on experimental work and observation of the material behavior. Results show that strain rate has some effect on the mechanical properties and deformation stability of the alloys. The area of localized plastic deformation and thickness of the shear bands were found to be sensitive to the strain rate. It was also observed that localization of plastic deformation and shear band formation is an important step in the damage propagation and final fracture of the alloys. Detail of damage development, based upon micrographs of samples interrupted at different stages of straining is presented

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