Temperature dependence of yield stress, tensile elongation and deformation structures in polysynthetically twinned crystals of Ti-Al

1995 ◽  
Vol 72 (6) ◽  
pp. 1609-1631 ◽  
Author(s):  
H. Inui ◽  
K. Kishida ◽  
M. Misaki ◽  
M. Kobayashi ◽  
Y. Shirai ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Yield Stress ◽  
Tensile Elongation ◽  
Deformation Structures

Deformation and its Structure in Llo Ti-Al-Nb Compound Alloys

1988 ◽  
Vol 133 ◽  
Author(s):  
Yoo-Dong Hahn ◽  
Sung H. Whang
Keyword(s):  
Temperature Dependence ◽  
Yield Stress ◽  
Uniaxial Compression ◽  
High Temperatures ◽  
Room Temperature ◽  
Fracture Strain ◽  
Positive Temperature ◽  
Deformation Structures ◽  
Miniature Specimens ◽  
Deformation Tests

ABSTRACTThe ternary TiAl-Nb (Llo) alloys stabilized at 1000°C for a week were prepared into miniature specimens for compressive deformation tests. The specimens were deformed in uniaxial compression at room temperature as well as various high temperatures. The yield stress and fracture strain were determined with respect to Nb concentration, and as a function of temperature to investigate positive temperature dependence.Dislocation structures and other deformation structures of the deformed alloys were studied by TEM.

Temperature Dependence of the Yield Stress in α-Titanium Investigated with Crystal Plasticity Analysis

2018 ◽  
Vol 941 ◽  
pp. 1474-1478
Author(s):  
Yelm Okuyama ◽  
Masaki Tanaka ◽  
Tetsuya Ohashi ◽  
Tatsuya Morikawa
Keyword(s):  
Finite Element ◽  
Temperature Dependence ◽  
Yield Stress ◽  
Crystal Plasticity ◽  
Slip Systems ◽  
Temperature Dependent ◽  
Element Analysis ◽  
Pyramidal Slip ◽  
Active Slip ◽  
Lattice Friction

The effect of the activated slip systems on the temperature dependence of yield stress was investigated in α-Ti by using crystal plasticity finite element method. A model for finite element analysis (FEA) was constructed based on experimental results. The displacement in FEA was applied up to the nominal strain of 4% which is the same strain as the experimental one. Stress-strain curves were obtained, which corresponds to experimental data taken every 50 K between 73 K and 673 K. The used material constants which are temperature dependent were elastic constants, and lattice friction stresses. The lattice friction stresses of basal slip systems were set to be higher than that of pyramidal slip systems at 73 K. Then, the lattice friction stresses were set to be closer as the temperature increases. It was found that the activation of slip systems is strong temperature dependent, and that the yield stress depends on the number of active slip systems.

The plasticity and cleavage of polycrystalline beryllium I. Yield and flow stresses

1980 ◽  
Vol 370 (1740) ◽  
pp. 17-27 ◽  
Keyword(s):  
Grain Size ◽  
Flow Stress ◽  
Dislocation Density ◽  
Temperature Dependence ◽  
Yield Stress ◽  
Dislocation Motion ◽  
Orientation Factor ◽  
High Rigidity ◽  
Rigidity Modulus

The dependence of the yield and flow stresses of vacuum-cast and extruded polycrystalline beryllium on the grain size, d, is studied over 20-400 °C. Both follow the standard d -1/2 relationship. The Taylor orientation factor in the deformation of the poly crystal is ca. 4.3. The marked temperature dependence of the yield stress between 20 and 200 °C arises primarily from the intragranular resistance to dislocation motion, in particular on prismatic planes. The variation of the flow stress with d1/2 increases progressively with strain and this is attributed to the effect of grain size on the dislocation density at a given strain; the increase is particularly marked for beryllium because of its high rigidity modulus.

Strain Rate Dependence of the Flow Stress and Work-Hardening of Single Crystals of NI3(Al,Hf)B

1994 ◽  
Vol 364 ◽  
Author(s):  
S. S. Ezz ◽  
Y. Q. Sun ◽  
P. B. Hirsch
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Yield Stress ◽  
Strain Rate Sensitivity ◽  
Work Hardening ◽  
Room Temperature ◽  
Rate Sensitivity ◽  
Controlling Mechanism

AbstractThe strain rate sensitivity ß of the flow stress τ is associated with workhardening and β=(δτ/δln ε) is proportional to the workhardening increment τh = τ - τy, where τy is the strain rate independent yield stress. The temperature dependence of β/τh reflects changes in the rate controlling mechanism. At intermediate and high temperatures, the hardening correlates with the density of [101] dislocations on (010). The nature of the local obstacles at room temperature is not established.

Orientation and temperature dependence of yield stress and slip geometry of Ti3Al and Ti3Al-V single crystals

1993 ◽  
Vol 41 (4) ◽  
pp. 1149-1154 ◽  
Author(s):  
Y. Umakoshi ◽  
T. Nakano ◽  
T. Takenaka ◽  
K. Sumimoto ◽  
T. Yamane
Keyword(s):  
Temperature Dependence ◽  
Single Crystals ◽  
Yield Stress
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