Plasticity During Fracture of the Au/Al2O3 Interface

1989 ◽  
Vol 170 ◽  
Author(s):  
Ivar E. Reimanis
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Fracture Energy ◽  
Stress Corrosion ◽  
Optical Microscope ◽  
Mechanical Tests ◽  
Interface Fracture ◽  
Fracture Surfaces ◽  
Topographic Features

AbstractAu/Al2 O3 interfaces are created by bonding highly textured Au films (25 pm thick) to single crystal A12 O3. Mechanical tests are done under the optical microscope to examine the effect of plastic deformation on the energy of fracture of the interface. Fracture occurs at the interface and is accompanied by plastic deformation in the Au. The relatively large value for the fracture energy measured (50-70J/m2) is attributed to the plastic deformation in the Au. It is also observed that fracture occurs subcritically due to stress corrosion at fracture energies from 10-20J/m2. Topographic features on the fracture surfaces are characterized and discussed briefly.

Mechanism of Stress Corrosion Cracking of Low Alloy Steel in Water

CORROSION ◽  
1981 ◽  
Vol 37 (6) ◽  
pp. 320-327 ◽  
Author(s):  
Wu-Yang Chu ◽  
Tian-Hua Liu ◽  
Chi-Mei Hsiao ◽  
Shi-Qun Li
Keyword(s):  
Plastic Deformation ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Cathodic Polarization ◽  
Optical Microscope ◽  
Corrosion Cracking ◽  
Low Alloy Steels ◽  
Wide Range ◽  
Alloy Steels ◽  
Loaded Crack

Abstract For four low alloy steels with a wide range of tensile strengths, the dynamical processes of the nucleation and propagation of stress corrosion cracking (SCC) in water with various polarization conditions and in a inhibitor solution were traced with an optical microscope. The results show that if the tensile strength of the steel is higher than a critical value, which is different in the different polarization conditions, and KI>KISCC, the plastic zone in front of a loaded crack tip is enlarged with time, i.e., the delayed plastic deformation occurs in all the environments used. The nucleation and propagation of SCC will follow when this delayed plastic deformation develops to a critical condition. Neither anodic and cathodic polarization nor the inhibitor can change the feature of the delayed plasticity and the nucleation and propagation of SCC in water. In all the environments used, the KISCC is increased and da/dt is decreased with decreasing strength of the steel. Anodic polarization and the addition of the inhibitor make KISCC increase and da/dt decrease. But cathodic polarization is just opposite.

Control of Osteoblastic Cell Behavior by Surface Topography Introduced by Plastic Deformation of Ti Single Crystal with h.c.p. Structure

2012 ◽  
Vol 706-709 ◽  
pp. 549-552
Author(s):  
Aira Matsugaki ◽  
Gento Aramoto ◽  
Takuya Ishimoto ◽  
Takayoshi Nakano
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Biological Tissues ◽  
Acute Angle ◽  
Surface Pattern ◽  
Cell Behavior ◽  
Osteoblastic Cell ◽  
Topographic Features ◽  
Schmid Factor ◽  
Slip Traces

Cells are known to sense the topographic features of the substrate and align along the direction of the surface pattern, and this is believed to be an important aspect in the formation and regeneration of anisotropic biological tissues. In this study, a unique and anisotropic stepped pattern was produced on single crystals of α-Ti with the h.c.p. lattice by plastic deformation in compression to demonstrate the effect of the pattern on cell behavior. Because the Schmid factor for the operative slip system of prismatic (100)[110] was set to be 0.5, the slip traces with an acute angle of 45° appeared on the surface. A smooth substrate without plastic deformation was used as a control. MC3T3-E1 osteoblastic cells were cultured on the substrate for 24 h, followed by observation of the morphology and alignment of the cells by Giemsa staining. On stepped substrates, cells aligned along the slip traces, and the filopodia of the aligned cells were found to extend parallel to the slip traces. The slip traces induced by plastic deformation of a single crystal was successfully proven to be a potent substrate to control the alignment of cells.

Micromachining Imposed Subsurface Plastic Deformation in Single-Crystal Aluminum

2020 ◽  
Author(s):  
Sudhanshu Nahata ◽  
Marzyeh Moradi ◽  
Yoosuf N. Picard ◽  
Nithyanand Kota ◽  
O. Burak Ozdoganlar
Keyword(s):  
Plastic Deformation ◽  
Single Crystal

scholarly journals Characterisation of Plasticity Response for Reciprocating Sliding Wear Test of Ti-6Al-4V under Variables Number of Cycles

2015 ◽  
Vol 773-774 ◽  
pp. 168-172
Author(s):  
D. Harun ◽  
D. Nalatambi ◽  
Ramdziah Md. Nasir ◽  
Abdul Latif Mohd Tobi
Keyword(s):  
Plastic Deformation ◽  
Titanium Alloy ◽  
Sliding Wear ◽  
Wear Track ◽  
Wear Test ◽  
Optical Microscope ◽  
Variable Number ◽  
Reciprocating Sliding ◽  
Number Of Cycles ◽  
Reciprocating Sliding Wear

Reciprocating sliding wear test of uncoated titanium alloy, Ti-6Al-4V is investigated using pin-on-flat contact arrangement of Ti-6Al-4V/Ti-6Al-4V pair under variable number of cycles at low number of cycles. The worn surfaces of the titanium alloy specimens were analyzed with the use of optical microscope (2D and 3D OM) and Vickers Hardness analysis was carried on. The pattern of the wear scar characteristics determined and the finding at the end of wear track had been focus through the presence at the end of wear track. It is suggesting an evidence of plastic deformation with the increasing in hardness value. The increase in hardness value at the end of wear track indicates increase in the plastic deformation with increasing number of cycles.

scholarly journals Microstructural Characterization and Mechanical Properties of Ti-6Al-4V Alloy Subjected to Dynamic Plastic Deformation Achieved by Multipass Hammer Forging with Different Forging Temperatures

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Xiurong Fang ◽  
Jiang Wu ◽  
Xue Ou ◽  
Fuqiang Yang
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Optical Microscope ◽  
Strain Rates ◽  
Materials Properties ◽  
Forging Process ◽  
Hammer Forging ◽  
Dynamic Plastic Deformation

Dynamic plastic deformation (DPD) achieved by multipass hammer forging is one of the most important metal forming operations to create the excellent materials properties. By using the integrated approaches of optical microscope and scanning electron microscope, the forging temperature effects on the multipass hammer forging process and the forged properties of Ti-6Al-4V alloy were evaluated and the forging samples were controlled with a total height reduction of 50% by multipass strikes from 925°C to 1025°C. The results indicate that the forging temperature has a significant effect on morphology and the volume fraction of primary α phase, and the microstructural homogeneity is enhanced after multipass hammer forging. The alloy slip possibility and strain rates could be improved by multipass strikes, but the marginal efficiency decreases with the increased forging temperature. Besides, a forging process with an initial forging temperature a bit above β transformation and finishing the forging a little below the β transformation is suggested to balance the forging deformation resistance and forged mechanical properties.

scholarly journals Molecular Dynamics Simulation of Crack Propagation in Single-Crystal Aluminum Plate with Central Cracks

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Jun Ding ◽  
Lu-sheng Wang ◽  
Kun Song ◽  
Bo Liu ◽  
Xia Huang
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Crack Propagation ◽  
Strain Rate ◽  
Single Crystal ◽  
Crack Length ◽  
Crack Growth ◽  
Plastic Yield ◽  
Model Size ◽  
Dislocation Multiplication

The crack propagation process in single-crystal aluminum plate (SCAP) with central cracks under tensile load was simulated by molecular dynamics method. Further, the effects of model size, crack length, temperature, and strain rate on strength of SCAP and crack growth were comprehensively investigated. The results showed that, with the increase of the model size, crack length, and strain rate, the plastic yield point of SCAP occurred in advance, the limit stress of plastic yield decreased, and the plastic deformability of material increased, but the temperature had less effect and sensitivity on the strength and crack propagation of SCAP. The model size affected the plastic deformation and crack growth of the material. Specifically, at small scale, the plastic deformation and crack propagation in SCAP are mainly affected through dislocation multiplication and slip. However, the plastic deformation and crack propagation are obviously affected by dislocation multiplication and twinning in larger scale.

Reverse Plasticity in Nanoindentation

2007 ◽  
Vol 1049 ◽  
Author(s):  
Yongjiang Huang ◽  
Nursiani Indah Tjahyono ◽  
Jun Shen ◽  
Yu Lung Chiu
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Glass Transition ◽  
Single Crystal ◽  
Metallic Glasses ◽  
Deformation Mechanisms ◽  
Glass Transition Temperatures ◽  
Loading Rates ◽  
Nanoindentation Experiment ◽  
Properties Of Materials

AbstractThis paper summarises our recent cyclic nanoindentation experiment studies on a range of materials including single crystal and nanocrystalline copper, single crystal aluminium and bulk metallic glasses with different glass transition temperatures. The unloading and reloading processes of the nanoindentation curves have been analysed. The reverse plasticity will be discussed in the context of plastic deformation mechanisms involved. The effect of loading rates on the mechanical properties of materials upon cyclic loading will also be discussed.

Nanoindentation Characterization of Single-Crystal Silicon With Oxide Film

2021 ◽  
Author(s):  
Lianmin Yin ◽  
Yifan Dai ◽  
Hao Hu
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Oxide Film ◽  
Single Crystal ◽  
Deformation Zone ◽  
Single Crystal Silicon ◽  
Plastic Deformation Zone ◽  
Crystal Silicon ◽  
Ultra Precision

Abstract In order to obtain ultra-smooth surfaces of single-crystal silicon in ultra-precision machining, an accurate study of the deformation mechanism, mechanical properties, and the effect of oxide film under load is required. The mechanical properties of single-crystal silicon and the phase transition after nanoindentation experiments are investigated by nanoindentation and Raman spectroscopy, respectively. It is found that pop-in events appear in the theoretical elastic domain of single-crystal silicon due to the presence of oxide films, which directly leads the single crystal silicon from the elastic deformation zone into the plastic deformation zone. In addition, the mechanical properties of single-crystal silicon are more accurately measured after it has entered the full plastic deformation.

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