The Role of Texture, Temperature and Strain Rate in the Activity of Deformation Twinning

2005 ◽  
Vol 495-497 ◽  
pp. 1037-1042 ◽  
Author(s):  
Donald W. Brown ◽  
Sean R. Agnew ◽  
S.P. Abeln ◽  
W.R. Blumenthal ◽  
Mark A.M. Bourke ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Deformation Mode ◽  
Relative Activity ◽  
Deformation Twinning ◽  
Underlying Structure ◽  
Cubic Metals ◽  
Pyramidal Slip ◽  
Crystallographic Symmetry

Plastic deformation in cubic metals is relatively simple due to the high crystallographic symmetry of the underlying structure. Typically, one unique slip mode can provide arbitrary deformation. This is not true in lower symmetry hexagonal metals, where prismatic and basal slip (the usual favored modes) are insufficient to provide arbitrary deformation. Often, either pyramidal slip and/or deformation twinning must be activated to accommodate imposed plastic deformation. The varied difficulty of activating each of these deformation mechanisms results in a highly anisotropic yield surface and subsequent mechanical properties. Further, the relative activity of each deformation mode may be manipulated through control of the initial crystallographic texture, opening new opportunities for the optimization of mechanical properties for a given application.

Polarization of plastic deformation modes in polysynthetically twinned TiAl crystals

2003 ◽  
Vol 18 (3) ◽  
pp. 702-708 ◽  
Author(s):  
V. Paidar ◽  
K. Kishida ◽  
M. Yamaguchi
Keyword(s):  
Plastic Deformation ◽  
Deformation Mode ◽  
Deformation Twinning ◽  
Additional Stress ◽  
Burgers Vector ◽  
Stress Increase ◽  
Loading Direction ◽  
Deformation Modes ◽  
Lamellar Interfaces

Polarization of deformation twinning (its propagation in a certain sense but not in the opposite one) is taken for granted. However, the same phenomenon can occur for a superdislocation glide as well, as is demonstrated in this paper. The consequences for plastic deformation of polysynthetically twinned TiAl crystals with the lamellar interfaces parallel to the loading direction are discussed. It is not the interface itself that is an obstacle for propagating deformation but also the fact that a deformation mode with the parallel Burgers vector cannot be activated in the neighboring lamella due to the directionality of superdislocation motion leading to additional stress increase.

Deformation Twinning, Slip, Martensite Formation and Crack Inhibition in the B2-Type Zr50Pd35Ru15 Alloy

1991 ◽  
Vol 246 ◽  
Author(s):  
R.M. Waterstrat ◽  
L.A. Bendersky ◽  
R. Kuentzler
Keyword(s):  
Crystal Structure ◽  
Plastic Deformation ◽  
Room Temperature ◽  
Deformation Mode ◽  
Deformation Twinning ◽  
Mechanical Twinning ◽  
Dislocation Slip ◽  
Slip Mode ◽  
Martensite Formation ◽  
Additional Mode

AbstractEnhanced room temperature toughness of the Zr50Pd35Ru15B2 phase alloy was found to be a result of the activation of an additional deformation mode besides the b=[001] dislocation slip mode - {114}-type mechanical twinning. The twinning is a true one, i.e. there is no change in the ordered crystal structure. Another additional mode of plastic deformation, expected for more Pd rich alloys, is the formation of stress-induced martensite. The martensite was found to have a CrBtype structure.

Influence Study of the Plastic Deformation Mode on the Micro-Indentation Mechanical Properties for the Pure Molybdenum

2021 ◽  
Vol 894 ◽  
pp. 39-43
Author(s):  
Jiang Li ◽  
Peng Fa Feng ◽  
Fu Guo Li ◽  
Qing Hua Li ◽  
Lin Lin Duan
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Powder Metallurgy ◽  
Deformation Mode ◽  
Indentation Hardness ◽  
Pure Molybdenum ◽  
Apparent Modulus ◽  
Deformation Instability ◽  
Deformation Modes ◽  
Micro Indentation

Four different plastic deformation modes of pure molybdenum in powder metallurgy were studied, including single tensile, single torsion, tensile-torsion and compressive-torsion. Then the influence of these four plastic deformation modes on the micro-mechanical properties of pure molybdenum in powder metallurgy was studied by the micro-indentation method. The results show that the accumulated strain before deformation instability or fracture of the studied material caused by different plastic deformation modes is different, while showing a regular variation. And the mean indentation hardness along the radial direction of the sample also change regularly, which results in different strengthening effects on the molybdenum material itself. The damage inside the deformed material will cause the apparent modulus of elasticity measured by micro-indentation to decrease significantly.

Mechanical properties of Fe-based bulk glassy alloys in Fe–B–Si–Nb and Fe–Ga–P–C–B–Si systems

2003 ◽  
Vol 18 (6) ◽  
pp. 1487-1492 ◽  
Author(s):  
A. Inoue ◽  
B. L. Shen ◽  
A. R. Yavari ◽  
A. L. Greer
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Vickers Hardness ◽  
Glassy Alloy ◽  
High Strength ◽  
Deformation Mode ◽  
Soft Magnetic Materials ◽  
Elastic Plastic ◽  
Glassy Alloys ◽  
Hardness Tests

Mechanical properties of cast Fe-based bulk glassy alloy rods with compositions of (Fe0.75B0.15Si0.1)96Nb4 and Fe77Ga3P9.5C4B4Si2.5 were examined by compression and Vickers hardness tests. The Young's modulus (E), yield strength (σy), fracture strength (σf), elastic strain (εe), fracture strain (εf), and Vickers hardness (Hv) were 175 GPa, 3165 MPa, 3250 MPa, 1.8%, 2.2%, and 1060, respectively, for the former alloy and 182 GPa, 2980 MPa, 3160 MPa, 1.9%, 2.2%, and 870, respectively, for the latter alloy. The εf /E and Hv/3E were 0.019–0.017 and 0.020–0.016, respectively, for the alloys, in agreement with the previous data for a number of bulk glassy alloys. The agreement suggests that these Fe-based bulk glassy alloys have an elastic–plastic deformation mode. The syntheses of high-strength Fe-based bulk glassy alloys with distinct compressive plastic strain and elastic–plastic deformation mode are encouraging for future development of Fe-based bulk glassy alloys as structural and soft magnetic materials.

Deformation of Transformation Toughened Zirconia

1986 ◽  
Vol 78 ◽  
Author(s):  
James Lankford
Keyword(s):  
Plastic Deformation ◽  
Flow Behavior ◽  
Deformation Mode ◽  
Grain Boundary Sliding ◽  
Shear Stresses ◽  
State Of Stress ◽  
Boundary Sliding ◽  
Recent Experimental Work ◽  
Temperature Strain

ABSTRACTRecent experimental work on the yield and flow behavior of both single crystal and polycrystalline transformation toughened zirconia is presented. In addition, related work by other researchers is reviewed. The resulting picture is used to assess the relative plastic deformation contributions of phase transformations, dislocation activity, and grain boundary sliding. Particular emphasis is placed on the effects of stabilizer chemistry, grain size, temperature, strain rate, and state of stress. The results are shown to reflect the strong role of shear stresses in selecting, and controlling the operation of, each deformation mode.

Compression deformation behavior of Zircaloy-4 alloy changing with activated twinning type at ambient temperature: experiment and modeling

2016 ◽  
Vol 49 (3) ◽  
pp. 987-996 ◽  
Author(s):  
Hongjia Li ◽  
Wupeng Cai ◽  
Zhijian Fan ◽  
Xuefei Huang ◽  
Yandong Wang ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Ambient Temperature ◽  
Deformation Behavior ◽  
Texture Evolution ◽  
Deformation Mode ◽  
Deformation Twinning ◽  
Rolled Plate ◽  
Strain Partitioning ◽  
Stress Strain ◽  
Plastic Deformation Behavior

It is widely accepted that twinning is important for the plastic deformation of zirconium alloys, although the corresponding roles of different types of twinning are rarely discussed. Here, the deformation behavior of Zircaloy-4 alloy at ambient temperature under compression along the rolling, transverse and normal directions of the rolled plate is studied by examination of macroscopic stress–strain curves, texture evolution andin situlattice strain, combined with elastic–plastic self-consistent simulation. It is concluded that tensile twinning {10\overline 12}〈10\overline 11〉, tensile twinning {11\overline 21}〈11\overline 26〉 and compressive twinning {11\overline 22}〈11\overline 2\overline 3〉 are the main deformation twinning types for compression along the three principal directions. A change in the activated twinning type induces differences in the plastic deformation mode and the stress/strain partitioning between parent and child grains. The work provides insight into the effects of deformation twinning on the plastic deformation behavior of Zircaloy-4 alloy.

Deformation Twinning and Change in Mechanical Properties of Cu-15at%Al in Multi-Pass Cold Rolling

2018 ◽  
Vol 941 ◽  
pp. 1523-1528 ◽  
Author(s):  
Sang Min Lee ◽  
Yong Deok Im ◽  
Ryo Matsumoto ◽  
Hiroshi Utsunomiya
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Cold Rolling ◽  
Tensile Test ◽  
Shear Bands ◽  
Hardness Test ◽  
Deformation Twinning ◽  
Al Alloys ◽  
Electron Backscattering Diffraction

Recently, it was reported that Cu-Al alloys of low stacking fault energy (SFE) processed by severe plastic deformation show excellent tensile properties due to TWIP (Twinning induced Plasticity) phenomenon. In this study, Cu-15at% Al sheets were heavily processed by conventional multi-pass cold rolling up to 90% in reduction in thickness without annealing. In order to reveal the change in mechanical properties and the microstructure evolution, tensile test, hardness test, optical microscopy (OM) and electron backscattering diffraction (EBSD) analysis were performed. Deformation twinning due to low SFE is observed even in the case of low reduction in thickness. As the reduction increases, grains are refined by intersections of shear bands. It is found that the balance of strength and elongation of the processed sheets is comparable to those by severe plastic deformation followed by annealing in literature.

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