Ti-Based Bulk Metallic Glass with High Cold Workability at Room Temperature

2005 ◽  
Vol 475-479 ◽  
pp. 3431-3434 ◽  
Author(s):  
J.M. Park ◽  
J.S. Park ◽  
J.H. Kim ◽  
Myung Hyun Lee ◽  
Won Tae Kim ◽  
...  
Keyword(s):  
Plastic Strain ◽  
Metallic Glass ◽  
Cold Rolling ◽  
Metallic Glasses ◽  
Room Temperature ◽  
Shear Bands ◽  
Reduction Ratio ◽  
Large Plastic Strain ◽  
Cold Rolled ◽  
Cold Workability

The cold workability of Ti-based bulk metallic glasses (BMGs) have been investigated. Ti45Zr16Be20Cu10Ni9 BMG with a large compressive plastic strain of 4.7 % shows a high cold workability, i.e. total reduction ratio of 50 % by cold rolling at room temperature. The multiple shear bands formed during rolling are effective in enhancing the plasticity. The cold rolled Ti45Zr16Be20Cu10Ni9 BMG (reduction ratio: 30 %) exhibits a large plastic strain of ~14 %.

Effects of Cold-Rolling Reduction on Microstructure and Mechanical Properties of Ti50Zr30Nb10Ta10 Alloy

2016 ◽  
Vol 849 ◽  
pp. 376-381
Author(s):  
Ming Long Li ◽  
Yu Jie Geng ◽  
Chen Chen ◽  
Shu Jie Pang ◽  
Tao Zhang
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Plastic Strain ◽  
Cold Rolling ◽  
Reduction Ratio ◽  
High Fracture ◽  
Dendrite Structure ◽  
Microstructure And Mechanical Properties ◽  
Cold Rolling Reduction ◽  
Cold Rolled

The effects of cold-rolling with different reduction ratios of 70%-90% on the microstructure and mechanical properties of Ti50Zr30Nb10Ta10 alloy were investigated. It was found that the β-Ti phase in this alloy was stable under cold-rolling. With the increase in reduction ratio from 70% to 90%, the microstructure of the alloys evolved from deformed dendrite structure to fiber-like structure. The alloy cold-rolled with the reduction ratio of 70% exhibited optimum mechanical properties of combined high fracture strength of 1012 MPa and plastic strain of 10.1%, which are closely correlated with the dendrite structure of the alloy. It is indicated that the proper cold-rolling is an effective way to improve the mechanical properties of the titanium alloy.

scholarly journals The Prospects for Mechanical Ratcheting of Bulk Metallic Glasses

2003 ◽  
Vol 806 ◽  
Author(s):  
Wendelin J. Wright ◽  
R. H. Dauskardt ◽  
W. D. Nix
Keyword(s):  
Plastic Strain ◽  
Metallic Glasses ◽  
Room Temperature ◽  
Tensile Axis ◽  
Uniaxial Stress ◽  
Temperature Deformation ◽  
Steel Alloys ◽  
Cyclic Torsion ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

ABSTRACTThe major mechanical shortcoming of metallic glasses is their limited ductility at room temperature. Monolithic metallic glasses sustain only a few percent plastic strain when subjected to uniaxial compression and essentially no plastic strain under tension. Here we describe a room temperature deformation process that may have the potential to overcome the limited ductility of monolithic metallic glasses and achieve large plastic strains. By subjecting a metallic glass sample to cyclic torsion, the glass is brought to the yield surface; the superposition of a small uniaxial stress (much smaller than the yield stress) should then produce increments in plastic strain along the tensile axis. This accumulation of strain during cyclic loading, commonly known as ratcheting, has been extensively investigated in stainless and carbon steel alloys, but has not been previously studied in metallic glasses. We have successfully demonstrated the application of this ratcheting technique of cyclic torsion with superimposed tension for polycrystalline Ti–6Al–4V. Our stability analyses indicate that the plastic deformation of materials exhibiting elastic–perfectly plastic constitutive behavior such as metallic glasses should be stable under cyclic torsion, however, results obtained thus far are inconclusive.

Compressive Plasticity of Zr-Based Bulk Metallic Glass at Low Temperature

2012 ◽  
Vol 443-444 ◽  
pp. 583-586
Author(s):  
Ya Juan Sun ◽  
Ri Ga Wu ◽  
Hong Jing Wang
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Low Temperatures ◽  
Room Temperature ◽  
Shear Bands ◽  
Strain Curve ◽  
Testing Temperature ◽  
Stress Strain Curve

The mechanical properties of a new Zr-based bulk metallic glass at low temperatures were investigated. The results indicate that the fracture strength increases significantly (4.9%) and the global plasticity increases somewhat when testing temperature is lowered to 123K. The stress-strain curve of the sample deformed exhibits more serrations and smaller stress drop due to formation of more shear bands at low temperature than at room temperature.

Amorphous Phase Formation in NiTi During Cold Rolling

1990 ◽  
Vol 186 ◽  
Author(s):  
J. Koike ◽  
D. M. Parkin ◽  
M. Nastasi
Keyword(s):  
Shear Stress ◽  
Room Temperature ◽  
Shear Bands ◽  
Mechanical Instability ◽  
Microstructural Morphology ◽  
Cold Rolled ◽  
Pure Metals ◽  
State Amorphization ◽  
Amorphous Phase Formation ◽  
Crystalline Matrix

AbstractThe intermetallic compound NiTi was cold rolled at room temperature. Amorphous bands were formed within the finely twined crystalline matrix after thickness reduction of 60%. Striking similarities were observed in microstructural morphology between amorphous bands and shear bands that are generally observed in heavily cold-rolled pure metals. We suggest from the present observations together with the reported results in other solid-state amorphization experiments that the amorphous bands are produced in the shear bands, and that amorphization is caused by mechanical instability against the shear stress.

Survival of Goss Grains during Cold Rolling of a Silicon Steel Single Crystal

2005 ◽  
Vol 495-497 ◽  
pp. 1061-1066 ◽  
Author(s):  
Dorothée Dorner ◽  
Ludger Lahn ◽  
Stefan Zaefferer
Keyword(s):  
Cold Rolling ◽  
Single Crystal ◽  
High Strain ◽  
Shear Bands ◽  
Rolling Process ◽  
Silicon Steel ◽  
Oriented Crystal ◽  
Cold Rolled ◽  
Goss Orientation ◽  
Crystal Volume

A silicon steel single crystal with initial Goss orientation, i.e. the {110}<001> orientation, was cold rolled up to 89 % thickness reduction. Most of the crystal volume rotates into the two symmetrical equivalent {111}<112> orientations. However, a weak Goss component is still present after high strain, although the Goss orientation is mechanically instable under plane strain loading. Two types of Goss-oriented crystal volumes are found in the highly deformed material. We suggest that their origin is different. The Goss-oriented regions that are observed within shear bands form during the cold rolling process. In contrast, those Goss-oriented crystal volumes that are found inside of microbands survive the cold rolling.

Ferromagnetic Resonance On Metallic Glass Ribbons

2001 ◽  
Vol 674 ◽  
Author(s):  
M. Chipara ◽  
M. Toacsen ◽  
M. Sorescu
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
External Magnetic Field ◽  
Metallic Glass ◽  
Ferromagnetic Resonance ◽  
Metallic Glasses ◽  
Room Temperature ◽  
Resonance Condition ◽  
X Band ◽  
Resonance Data

ABSTRACTFerromagnetic resonance data on metallic glasses, at room temperature, in X band, are discussed. The spectra were decomposed into two Lorentzian lines and the angular dependence of their main parameters (line width and position) is fully analyzed. It is proved that the usual approaches are not able to describe accurately the experimental data. This behavior is ascribed to the misalignment of the magnetization with respect to the external magnetic field, and successfully tested by using a “relaxed” resonance condition that allows a small misalignment of the magnetization relative to the external magnetic field.

Effect of Annealing Treatment on the Properties of Cold Rolled Copper Foil

2018 ◽  
Vol 921 ◽  
pp. 231-235
Author(s):  
Ke Bin Sun ◽  
Yan Feng Li ◽  
Ye Xin Jiang ◽  
Guo Jie Huang ◽  
Xue Shuai Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cold Rolling ◽  
Copper Foil ◽  
Room Temperature ◽  
Annealing Treatment ◽  
Test Machine ◽  
Cold Rolled ◽  
Rolled Copper Foil ◽  
Fracture Morphologies

Copper foils with 91% cold rolled deformation annealed at temperature between 140°C and 170 °C.The microstructures were observed by EBSD. The mechanical properties were measured at room temperature by tensile test machine and the fracture morphologies observed by SEM. After annealed at 150 °C, recrystallization begins to occur, while the elongation increases evidently and tensile strength decreases sharply. When the temperature rises to 170 °C, recrystallization is complete and the grain starts to grow. When the foils are annealed at 140 °C, it exhibits a strong cold rolling textures characterized by Brass {011}<211> and Cu {112}<111>. After annealed at 170 °C, there are olny weak Brass {011}<211> texture.

Scanning tunneling microscope observations of metallic glass fracture surfaces

1993 ◽  
Vol 8 (10) ◽  
pp. 2543-2553 ◽  
Author(s):  
D.M. Kulawansa ◽  
J.T. Dickinson ◽  
S.C. Langford ◽  
Yoshihisa Watanabe
Keyword(s):  
Fracture Surface ◽  
Metallic Glass ◽  
Metallic Glasses ◽  
Scanning Tunneling Microscope ◽  
Shear Bands ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Fracture Surfaces ◽  
Glass Fracture ◽  
Shear Instabilities

We report scanning tunneling microscope observations of fracture surfaces formed during catastrophic crack growth in three metallic glasses: Ni56Cr18Si22B4, Co69Fe4Ni1Mo2B12Si12, and Fe78B13Si9. Macroscopically, the first two glasses fail along a slip band formed during loading and display a characteristic, μm-scale pattern of vein-like ridges; in contrast, Fe78B13Si9 displays little slip prior to fracture, and its fracture surface shows a μm-scale chevron pattern of steps. STM observations of fracture surfaces of all three materials show nm-scale grooves. The grooves in Co69Fe4Ni1Mo2B12Si12 are especially prominent and display stepped edges which we attribute to the intersection of shear bands with the surface. STM observations of the vein-like features on Ni56Cr18Si22B4 also show stepped edges. We attribute the vein features to the interaction of adjacent crack fingers in which the material between adjacent fingers fails in plane stress. The origin of the grooves is uncertain, but may be due to other shear instabilities along crack fingers.

scholarly journals Effect of cold rolling and annealing temperature to the characteristics of α + β' phases in Cu-29.5Zn-2.5Al alloy produced by gravity casting

2020 ◽  
Vol 56 (1) ◽  
pp. 89-97
Author(s):  
I. Angela ◽  
I. Basori ◽  
B.T. Sofyan
Keyword(s):  
Cold Rolling ◽  
Shear Bands ◽  
X Ray Diffraction ◽  
Gravity Casting ◽  
X Ray ◽  
Low Temperature Annealing ◽  
Slip Bands ◽  
Cold Rolling And Annealing ◽  
Higher Temperature ◽  
Cold Rolled

Al-brass alloys (Cu29.5Zn2.5Al wt. %) were produced by gravity casting and homogenized at 800?C for 2 h, resulting in a binary phase morphology identified as cubic ? and martensitic ?? phases through X-ray diffraction (XRD). Samples were then subsequently cold rolled and annealed at 150, 300, 400, and 600?C for 30 minutes. Visible traces of slip, intersecting slip bands, and shear bands were observed in microstructure images of the samples after each progressive deformation stage. Deformation-induced martensites were present after 20 % cold rolling. Higher thickness reduction resulted in simultaneous strain hardening of the phases. Low temperature annealing slightly increased microhardness, of both ? and ??, due to the formation of precipitates. SEM-EDX analysis showed that no solute segregation was found in annealed samples. Annealing at higher temperature resulted in conventional softening. Recrystallized equiaxed ?? phase grains were visible after annealing at 600?C.

scholarly journals Improve the Forming Ability of Al-Based Metallic Glass Under Ultrasonic Vibration at Room Temperature

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiong Liang ◽  
Caitao Fan ◽  
Jianan Fu ◽  
Zehang Liu ◽  
Zhenxuan Zhang ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Ultrasonic Vibration ◽  
Metallic Glasses ◽  
Room Temperature ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Deformation Degree ◽  
Maximum Deformation ◽  
Primary Sample

In this work, a rapid and controllable ultrasonic vibration method for forming Al-based metallic glass at room temperature is proposed. This method can dramatically improve the forming ability of Al-based metallic glasses, which are virtually brittle at room temperature and have almost no supercooled liquid region at high temperatures. Under ultrasonic vibration, Al-based metallic glasses exhibited obvious plastic flow, with a maximum deformation degree up to 58% and an average deformation degree up to 43%. It is worth mentioning that no crystalline peaks were found on the X-ray diffraction patterns after deformation under ultrasonic vibration, and the mechanical properties remained the same as the primary sample. The present results provide a new approach for the deformation and forming of Al-based metallic glasses, which can significantly broaden their applications.

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