Orientation Dependence of Ductility of Mg Single Crystals at Elevated Temperature

2005 ◽  
Vol 488-489 ◽  
pp. 193-196 ◽  
Author(s):  
Hiromi Miura ◽  
Taku Sakai ◽  
H. Nogawa ◽  
Xu Yue Yang ◽  
Yoshimi Watanabe ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Crystal Orientation ◽  
Fracture Strain ◽  
Orientation Dependence ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
High Ductility ◽  
Superplastic Behavior ◽  
Strong Orientation

Orientation-controlled Mg single crystals were tensile tested at temperatures between 473 K and 673 K at a strain rate of 4.2 x 10-4 s-1 in vacuum. Though all the single crystals showed high ductility compared with that of polycrystals, the ductility of the single crystals strongly depended on the crystal orientation. The [27 -1 -26 1] single crystal showed 0.57 fracture strain, while the [3 8 -11 -1] single crystal showed superplastic behavior of ductility over 1.8 strain. The observed strong orientation dependence of ductility seemed to be caused by orientation dependence of ease occurrence of dynamic recrystallization (DRX) in the single crystals during high-temperature deformation. The orientation dependence of ductility of Mg single crystals will be discussed in detail concerning crystallographical orientations of the single crystals, occurrence of DRX and fracture.

Orientation Dependence of Dynamic Recrystallization Behavior of Al Single Crystals

2004 ◽  
Vol 449-452 ◽  
pp. 31-36
Author(s):  
Yasuhiro Miura ◽  
Kentaro Ihara
Keyword(s):  
Dynamic Recrystallization ◽  
Single Crystals ◽  
Orientation Dependence ◽  
Crystallographic Analysis ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Stress Strain ◽  
Strain Behavior ◽  
The Matrix ◽  
Dynamic Recrystallization Behavior

An experimental study on the microstructure development and stress–strain behavior during high temperature deformation of aluminum (Al) single crystals was made by using X-ray Laue technique and the electron backscatter pattern (EBSP) technique. The main purpose was to clarify the process of dynamic recrystallization (DRX). The measured stress-strain curves with large stress peaks and the new Laue spots without streaks at around the stress peaks confirmed the occurrence of DRX in Al single crystals with initial compression axis <111>, <011> or <001>. Crystallographic analysis by the Laue technique and EBSP technique show that the DRX grain and the matrix have an <121> axis in common in the <111> crystal, an <101> axsis in the <011> and <001> crystals. For the <111> crystal, the unrecrystallized region near the DRX grain consists of subgrains adjoined each other with <112> tilt boundaries and the size of subgrains becomes smaller and the misfit at subgrain boundaries becomes larger as the DRX grain boundaries are approached. These results suggest that DRX grains are nucleated through the development of subgrains.

High Temperature Creep Behavior of Single Crystal Gammpraime and Gamm Laloys

1988 ◽  
Vol 133 ◽  
Author(s):  
M. V. Nathal ◽  
J. O. Diaz ◽  
R. V. Miner
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Creep Behavior ◽  
Dislocation Motion ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
High Temperature Creep ◽  
Two Phase ◽  
Temperature Creep

ABSTRACTThe creep behavior of single crystals of γ′ and γ alloys were investigated and compared to the response of two phase superalloys tested previously. High temperature deformation in the γ alloys was characteristic of a climb controlled mechanism, whereas the γ′ based materials exhibited glide controlled creep behavior. The superalloys were much more creep resistant than their constituent phases, which indicates the importance of the γ-γ′ interface as a barrier for dislocation motion during creep.

scholarly journals High-Strength Behavior of the Al0.3CoCrFeNi High-Entropy Alloy Single Crystals

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1149
Author(s):  
Irina V. Kireeva ◽  
Yuriy I. Chumlyakov ◽  
Zinaida V. Pobedennaya ◽  
Anna V. Vyrodova ◽  
Anastasia A. Saraeva
Keyword(s):  
Single Crystals ◽  
Yield Point ◽  
Stress Level ◽  
High Stress ◽  
High Strength ◽  
Orientation Dependence ◽  
Temperature Deformation ◽  
High Entropy Alloy ◽  
Shear Stresses ◽  
High Entropy

The main disadvantage of fcc (face-centred cubic lattice) high-entropy alloys is the low stress level at the yield point (σ0.1) at a test temperature above room temperature. This restricts their practical application at high test temperatures from 773 K to 973 K. In this study, we found that a high stress level was reached at the yield point σ0.1 ≈ G/100–G/160 (G is the shear modulus) of the [001]- and [1¯44]-oriented crystals of the Co23.36Cr23.29Fe23.80Ni21.88Al7.67 (Al0.3CoCrFeNi) high-entropy alloy (HEA) within a wide temperature range of 77–973 K under tension, due to the occurrence, of nanotwins, multipoles, dislocations under plastic deformation at 77 K and the subsequent precipitation of ordered L12 and B2 particles. It was shown that grain boundaries are not formed and the samples remain in a single-crystal state after low-temperature deformation and subsequent ageing at 893 K for 50 h. Achieving a high-strength state in the Al0.3CoCrFeNi HEA single crystals induces the orientation dependence of the critical resolved shear stresses (τcr) at T ≥ 200 K (τcr[1¯44] > τcr[001]), which is absent in the initial single-phase crystals, weakens the temperature dependence of σ0.1 above 573 K, and reduces plasticity to 5–13% in the [1¯44] orientation and 15–20% in the [001] orientation.

Structure and mechanical properties of an Ni3Al single crystal upon high-temperature deformation

2011 ◽  
Vol 111 (4) ◽  
pp. 403-409 ◽  
Author(s):  
N. N. Stepanova ◽  
D. I. Davydov ◽  
D. P. Rodionov ◽  
Yu. I. Philippov ◽  
Yu. N. Akshentsev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Single Crystal ◽  
High Temperature Deformation ◽  
Temperature Deformation

Structure and magnetic properties of a Ni3(Al, Fe, Cr) single crystal subjected to high-temperature deformation

2016 ◽  
Vol 117 (5) ◽  
pp. 451-459 ◽  
Author(s):  
N. V. Kazantseva ◽  
M. B. Rigmant ◽  
N. N. Stepanova ◽  
D. I. Davydov ◽  
D. A. Shishkin ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
High Temperature ◽  
Single Crystal ◽  
High Temperature Deformation ◽  
Temperature Deformation

THE EFFECT OF ADDITION AGENTS ON CATHODE POLARIZATION DURING ELECTRODEPOSITION OF COPPER AT SINGLE CRYSTAL COPPER CATHODES

1955 ◽  
Vol 33 (12) ◽  
pp. 1756-1767
Author(s):  
K. Ekler ◽  
C. A. Winkler
Keyword(s):  
Steady State ◽  
Single Crystal ◽  
Single Crystals ◽  
Linear Relation ◽  
Crystal Orientation ◽  
Chloride Ion ◽  
Addition Agent ◽  
Cathode Polarization ◽  
Single Crystal Copper ◽  
Copper Single Crystals

The polarization–time relations for the initial (Pi), maximum (Pmax), and pseudo-steady-state (Ps) polarizations on copper single crystals in the absence and presence of gelatin and gelatin plus chloride ion were found to depend upon crystal orientation. The Pi and Pmax in the absence of gelatin, the Pi in its presence, and the static potentials were all similarly related to the reticular density. The Pi increased, and the time to maximum polarization (tmax) decreased, with increase of current density; the relations between these quantities showed marked differences for the different crystals. The variation with reticular density of Pi and Pmax in the absence of addition agents and of Pi in its presence probably represents differences in activation overpotential at the various crystal faces. The adsorption of gelatin on different crystal faces was also found to be markedly different. Polarization in the presence of gelatin was decreased by small amounts of chloride ion; a linear relation for all the crystals used was obtained by plotting the increase in polarization caused by gelatin against the decrease caused by 2 mgm./liter chloride ion in the presence of gelatin. In the absence of addition agent, change of acid concentration from 50 to 200 gm./liter had no effect on Pi and addition of chloride ion had no effect on Ps at single crystal cathodes.

Orientation-dependent Constitutive Model with Nonlinear Elasticity for Shocked β-HMX Single Crystal

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Yan-Qing Wu ◽  
Feng-Lei Huang
Keyword(s):  
Constitutive Model ◽  
Single Crystal ◽  
Mechanical Behavior ◽  
Single Crystals ◽  
Nonlinear Elasticity ◽  
Chemical Reactions ◽  
Crystal Plasticity ◽  
Orientation Dependence ◽  
Plasticity Model ◽  
Crystal Plasticity Model

AbstractAs orientation-dependence of shock-induced thermal responses and chemical reactions in energetic single crystals are related to anisotropic mechanical behavior, a crystal plasticity model for low-symmetric

Sign in / Sign up

Export Citation Format

Share Document