The Mechanical Behavior and Deformation Mechanisms of Nb-Al-V Alloys

1996 ◽  
Vol 460 ◽  
Author(s):  
D. K. Tappin ◽  
D. N. Horspool ◽  
L. S. Smith ◽  
M. Aindow
Keyword(s):  
Mechanical Behavior ◽  
Room Temperature ◽  
Compression Testing ◽  
Deformation Mechanisms ◽  
Dislocation Activity ◽  
Partial Dislocations ◽  
Shear Transformation ◽  
B2 Phase ◽  
A15 Phase ◽  
Phase Strains

ABSTRACTA series of Nb-Al-V alloys containing 20–40 at. % V and 10–25 at. % Al have been investigated. The phase distributions in the alloys indicate that Al promotes the formation of the A15 phase whilst V stabilises a B2 phase. Room temperature compression testing revealed that the B2 is inherently ductile such that for the alloys with less than 40% by volume of the A15 phase, strains of over 50% were obtained easily. The 2% offset yield stresses of these alloys did not vary significantly with composition, being 1.2±0.1GPa in each case. TEM studies were used to show that the deformation in the B2 phase occurs predominantly by the glide of screw-type super-partial dislocations with b=l/2<111> on {110} and {112}. In some alloys this dislocation activity was preceded by the formation of pseudo-twins, via a martensitic shear transformation.

The Microstructure of Nb3Al-Mo Intermetallics

1994 ◽  
Vol 364 ◽  
Author(s):  
E. Passa ◽  
P. Tsakiropoulos
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Room Temperature ◽  
Rapid Quenching ◽  
Ternary Alloys ◽  
Complete Solid Solubility ◽  
Melt Spun ◽  
B2 Phase ◽  
Melt Spun Ribbons ◽  
A15 Phase

AbstractThe microstructure of arc melted ingots and melt-spun ribbons of Nb-18A1, Nb-18Al-(20–40) Mo (at%) were studied. Rapid quenching from the melt refined the grain size by at least two orders of magnitude. In the binary alloy ingots and ribbons the Nb3Al (A15) and B2 phases were present. Molybdenum exhibited complete solid solubility in the bcc Nb-Al solid solution as well as in the Nb3Al (A15 phase). The former was the only phase present in the ribbons of the ternary alloys, while Nb3Al was detected only in the ingots. B2 phase was formed in the alloy with 20 at% Mo and the A2 phase was present in the alloy with 40 at% Mo. Furthermore, Mo addition increased the room temperature microhardness of the Nb-Al solid solution by ≈7 Kgmm−2/ at%Mo.

Metastable Phases and Defect Microstructures in Melt-Spun Ribbons of Nb3Al

1990 ◽  
Vol 209 ◽  
Author(s):  
M. Aindow ◽  
J. Shyue ◽  
T.A. Gaspar ◽  
H.L. Fraser
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nominal Composition ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Melt Spun ◽  
B2 Phase ◽  
Melt Spun Ribbons ◽  
Defect Microstructures ◽  
A15 Phase

ABSTRACTThe phases and defects produced in a binary alloy, with nominal composition Nb-18at.% Al, have been studied using transmission electron microscopy (TEM). In addition to the equilibrium A15 phase (Nb3Al) a previously unreported Nb-rich B2 phase is present. A significant number of grow-in dislocations were observed in the A15 phase, these have b= a<100> and are predominantly screw on character. They are dissociated into two partial dislocations which bound a stacking fault according to the reaction;<100> → > 1/2 <100> + SF + 1/2 <100>The habit plane of the fault is shown to be {012}. These observations are compared with previous studies performed on the isostructual compound V3Si. The consequences of the observed dissociation for the plastic deformation of Nb3Al are discussed.

Microstructures, Defects and Deformation Mechanisms in Vanadium Modified Nb3Al

1993 ◽  
Vol 322 ◽  
Author(s):  
L.S. Smith ◽  
M. Aindow ◽  
M.H. Loretto
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Defect Structure ◽  
Electron Microscope Study ◽  
Deformation Mechanisms ◽  
Transmission Electron ◽  
Large Growth ◽  
Transmission Electron Microscope Study ◽  
B2 Phase ◽  
A15 Phase

AbstractA transmission electron microscope study of the microstructure and defect structure in vanadium modified Nb3Al and its deformation mechanisms is presented. Two alloys are examined in which 20 and 40 atomic % V is substituted for Nb. The former alloy exhibits a microstructure containing a stable A15 phase and a metastable B2 phase which transforms to A15 upon heat treatment. The A15 grains contain defects similar to those observed previously in binary Nb3Al: i.e. large growth faults with R=1/4<012> and dissociated dislocations with a separation of =15nm and b=1/2<001> bounding a stacking fault with R=1/2<001>. The alloy containing 40 atomic % V consists only of an equilibrium B2 phase and exhibits greatly enhanced ductility. Slip occurs by the glide of dislocations with b=<111> on {011}.

A comparative study of plastic deformation mechanisms in room-temperature and cryogenically deformed magnesium alloy AZ31

2021 ◽  
Vol 807 ◽  
pp. 140821
Author(s):  
Kai Zhang ◽  
Zhutao Shao ◽  
Christopher S. Daniel ◽  
Mark Turski ◽  
Catalin Pruncu ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Magnesium Alloy ◽  
Comparative Study ◽  
Room Temperature ◽  
Deformation Mechanisms ◽  
Alloy Az31 ◽  
Magnesium Alloy Az31

Toughening Mechanisms of Lamellar TiAl Alloys Containing B2 Phase at Room Temperature

2014 ◽  
Vol 43 (3) ◽  
pp. 540-543 ◽  
Author(s):  
Zhe Wang ◽  
Rui Cao ◽  
Jianhong Chen ◽  
Ji Zhang
Keyword(s):  
Room Temperature ◽  
Toughening Mechanisms ◽  
Tial Alloys ◽  
B2 Phase

Deformation Twins Formed in Nanocrystalline Materials

2006 ◽  
Vol 503-504 ◽  
pp. 125-132 ◽  
Author(s):  
Yuntian T. Zhu
Keyword(s):  
Grain Boundaries ◽  
Nanocrystalline Materials ◽  
Partial Dislocation ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Nucleation And Growth ◽  
Analytical Models ◽  
Partial Dislocations ◽  
Deformation Twins ◽  
Low Strain Rate

Deformation twins have been oberved in nanocrystalline (NC) Al synthsized by cryogenic ball-milling and in NC Cu processed by high-pressure torsion under room temperature and at a very low strain rate. They were found formed by partial dislocations emitted from grain boundaries. This paper first reviews experimental evidences on deformation twinning and partial dislocation emissions from grain boundaries, and then discusses recent analytical models on the nucleation and growth of deformation twins. These models are compared with experimental results to establish their validity and limitations.

On the room temperature deformation mechanisms of a TiZrHfNbTa refractory high-entropy alloy

2015 ◽  
Vol 645 ◽  
pp. 255-263 ◽  
Author(s):  
J.-Ph. Couzinié ◽  
L. Lilensten ◽  
Y. Champion ◽  
G. Dirras ◽  
L. Perrière ◽  
...  
Keyword(s):  
Room Temperature ◽  
Deformation Mechanisms ◽  
Temperature Deformation ◽  
High Entropy Alloy ◽  
High Entropy
Sign in / Sign up

Export Citation Format

Share Document