Plasticity Mechanisms in Multi-Scale Copper-Based Nanocomposite Wires

2007 ◽  
Vol 539-543 ◽  
pp. 814-819 ◽  
Author(s):  
Ludovic Thilly ◽  
Vanessa Vidal ◽  
Florence Lecouturier
Keyword(s):  
Plastic Deformation ◽  
Size Effects ◽  
Hot Extrusion ◽  
High Strength ◽  
Cold Drawing ◽  
High Yield ◽  
Multi Scale ◽  
Pulsed Magnets ◽  
In Situ Deformation

Copper-based high strength nanofilamentary wires reinforced by Nb nanofilaments are prepared by severe plastic deformation (repeated hot extrusion, cold drawing and bundling steps) for the winding of high pulsed magnets. The effects of microstructure refinement on the plasticity mechanisms were studied via nanoindentation, in-situ deformation in TEM and under neutron beam: all results evidence size effects in each nanostructured phase of the nanocomposite wires, i.e. single dislocation regime in the finest regions of the Cu matrix and whisker-like behaviour in the Nb nanofilaments. The macroscopic high yield stress is thus the results of the combination of the different elastic-plastic regimes of each phase that include size effects.

“In Situ” observation by Transmission Electron Microscope of the deformation and fracture micromechanisms in 7050 aluminum alloy

1990 ◽  
Vol 48 (4) ◽  
pp. 522-523
Author(s):  
W.A. Monteiro ◽  
O.E. Alarcon ◽  
A.M.M. Nazar
Keyword(s):  
Aluminum Alloy ◽  
High Strength ◽  
Propagation Mode ◽  
In Situ Observation ◽  
Brittle Behavior ◽  
Transmission Electron ◽  
Deformation And Fracture ◽  
7050 Aluminum Alloy ◽  
In Situ Deformation

During the last ten years the "in situ" deformation experiments by transmission electron microscopy have been used in metals to study the micromechanism of plastic deformation and fracture propagation mode occuring from the crack tip.These studies were performed in mono and policrystals metals with the aim to investigate the dislocation emission from crack tip phenomena relating it with the ductil versus brittle behavior of materials.The material used in this experiment was a high strength aluminum alloy 7050 contained recrystal1ized and unrecrystal1ized microstructures, as the obtained by thermomechanical treatment in previous work .Due to the small dimensions of the miniature tensile specimens (2.7 × 6.8 × 0.02 mm ) and the requisite to obtain a lot of samples without introduction of strain during manufacture, the specimens was performed using a lithographic process.

In Situ Deformation at 850°C of Standard and Rafted Microstructures of Nickel Base Superalloys

2006 ◽  
Vol 509 ◽  
pp. 57-62 ◽  
Author(s):  
Nicole Clément ◽  
Mustafa Benyoucef ◽  
M. Legros ◽  
Pierre Caron ◽  
Armand Coujou
Keyword(s):  
Plastic Deformation ◽  
Single Crystals ◽  
Stress Conditions ◽  
Actual Temperature ◽  
In Situ Study ◽  
The Creation ◽  
Nickel Base ◽  
In Situ Deformation

An in situ study of the plastic deformation of <001> single crystals of an industrial superalloy has been performed at 850 °C in a TEM to observe directly the micromechanisms which control the deformation under the actual temperature and stress conditions experienced by this material in aeroengines. A comparison between the creation and propagation modes of moving dislocations in the standard microstructure after annealing and the rafted microstructure after 20 h of creep at 1050°C evidence the important role of the width of the γ channels as well as the strength of the γ/γ’ interface in controlling the shearing events of γ’ channels.

Ultrahigh-Temperature Nb-Silicide-Based Composites

MRS Bulletin ◽  
2003 ◽  
Vol 28 (9) ◽  
pp. 646-653 ◽  
Author(s):  
B. P. Bewlay ◽  
M. R. Jackson ◽  
J.-C. Zhao ◽  
P. R. Subramanian ◽  
M. G. Mendiratta ◽  
...  
Keyword(s):  
Hot Extrusion ◽  
High Strength ◽  
Turbine Engines ◽  
Crack Growth Behavior ◽  
Potential Applications ◽  
Ultrahigh Temperature ◽  
And Performance ◽  
Induction Skull Melting ◽  
Powder Metallurgy Methods

AbstractThis article reviews the most recent progress in the development of Nb-silicide-based in situ composites for potential applications in turbine engines with service temperatures of up to 1350°C. These composites contain high-strength Nb silicides that are toughened by a ductile Nb solid solution. Preliminary composites were derived from binary Nb-Si alloys, while more recent systems are complex and are alloyed with Ti, Hf, W, B, Ge, Cr, and Al. Alloying schemes have been developed to achieve an excellent balance of room-temperature toughness, fatigue-crack-growth behavior, high-temperature creep performance, and oxidation resistance over a broad range of temperatures. Nb-silicide-based composites are described with emphasis on processing, microstructure, and performance. Nb silicide composites have been produced using a range of processing routes, including induction skull melting, investment casting, hot extrusion, and powder metallurgy methods. Nb silicide composite properties are also compared with those of Ni-based superalloys.

scholarly journals Young's Modulus of Iron–Silver Sheet Composites

1989 ◽  
Vol 10 (3) ◽  
pp. 227-242 ◽  
Author(s):  
L. Ratke
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Hot Extrusion ◽  
Rolling Plane ◽  
Elastic Behaviour ◽  
Strong Increase ◽  
Deformation Dependence ◽  
Experimental Findings ◽  
In Situ Deformation

Layered iron–silver sheet composites were prepared by hot extrusion and cold rolling of powder mixtures of various compositions. These in-situ deformation composites show a strong increase in Young's Modulus on addition of silver to pure iron and their elastic behaviour is anisotropic in the rolling plane. The deformation dependence of Young's Modulus as well as the planar anisotropy are discussed with a new theory of Bunge, which covers the experimental findings sufficiently.

Behavior of Heavy Plastic Deformation of Cu-15Cr-0.1Zr In Situ Composite

2009 ◽  
Vol 79-82 ◽  
pp. 2191-2194
Author(s):  
Yan Li ◽  
Xiao Hong Chen ◽  
Ping Liu ◽  
Lin Hua Gao ◽  
Bao Hong Tian
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
Cold Drawing ◽  
Degree Of Deformation ◽  
Transmission Electron ◽  
Fibrous Morphology ◽  
Two Phases ◽  
Relationship Of ◽  
The Relationship

The behavior of plastic deformation of Cu-15Cr-0.1Zr in-situ composite under different degree of cold drawing deformation was analyzed by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that both Cu and Cr phases are elongated along cold drawn direction and appear a fibrous morphology; However, Cu phase shows a thread-like fibrous morphology and Cr phase shows a band-like fibrous morphology. The two phases have a coherent relationship of (111)Cu //(011)Cr; When the degree of deformation(ε)is equal to 6.43, the relationship shows// [111]Cu // [110]Cr //cold drawn direction. Furthermore, forming two different morphologies of Cu and Cr phases during cold drawing is also analyzed.

In-situ SAXS study of the plastic deformation behavior of polylactide upon cold-drawing

Polymer ◽  
2014 ◽  
Vol 55 (7) ◽  
pp. 1817-1828 ◽  
Author(s):  
G. Stoclet ◽  
J.M. Lefebvre ◽  
R. Séguéla ◽  
C. Vanmansart
Keyword(s):  
Plastic Deformation ◽  
Deformation Behavior ◽  
Cold Drawing ◽  
Plastic Deformation Behavior

Size Effect in the Plasticity of Multiscale Nanofilamentary Cu/Nb Composite Wires During in-situ Tensile Tests Under Neutron Beam

2006 ◽  
Vol 977 ◽  
Author(s):  
Vanessa Vidal ◽  
Ludovic Thilly ◽  
Steven Van Petegem ◽  
Uwe Stuhr ◽  
Florence Lecouturier ◽  
...  
Keyword(s):  
Size Effect ◽  
Neutron Beam ◽  
Load Transfer ◽  
High Strength ◽  
Tensile Tests ◽  
Copper Matrix ◽  
Lattice Strains ◽  
Matrix Embedding ◽  
Pulsed Magnets

AbstractCopper-based high strength nanofilamentary wires reinforced by bcc nanofilaments (Nb or Ta) are prepared by severe plastic deformation for the winding of high pulsed magnets. In-situ tensile tests under neutron beam were performed on a Cu/Nb nanocomposite composed of a multiscale Cu matrix embedding 554 Nb filaments with a diameter of 267 nm and spacing of 45 nm. The evolution of elastic strains for individual lattice plane in each phase and peak profiles in the copper matrix versus applied stress evidenced the co-deformation behavior with different elastic-plastic regimes and load sharing: the Cu matrix exhibits size effect in the finest channels while the Nb nanowhiskers remain elastic up to the macroscopic failure, with a strong load transfer from the copper matrix onto zones that are still in the elastic regime. Taking into account results from residual lattice strains also determined by neutron diffraction, the yield stress in the finest Cu channels is in agreement with calculations based on a single dislocation regime.

Development of Seamless Pipes with Improved Strength-Toughness Combination for Hydraulic Cylinders

2007 ◽  
Vol 539-543 ◽  
pp. 4345-4350
Author(s):  
Claudio Guarnaschelli ◽  
P. Folgarait ◽  
E. Paravicini Bagliani ◽  
R. Demarchi ◽  
H. Desimone
Keyword(s):  
Laboratory Tests ◽  
High Strength ◽  
Cold Drawing ◽  
High Yield ◽  
High Yield Strength ◽  
Steel Pipes ◽  
Experimental Activity ◽  
Stress Relieving ◽  
Hydraulic Cylinders ◽  
Multi Phase

Steel pipes for hydraulic cylinders have to offer high strength levels and good toughness. A minimum value of 27 J at – 20 °C is typically requested. In this work, a comprehensive experimental activity based on both laboratory tests and industrial trials was performed in order to investigate the benefits related to the development of multi-phase microstructures in seamless pipes for hydraulic cylinders. The effect of these microstructures on strength and toughness were analyzed. Charpy V-notch (CVN) impact tests showed that toughness increases monotonically with the increase of the intercritical temperature, i.e. when the carbon content of the newly formed austenite is reduced. Industrial trials were performed on tubes applying a proper inter-critical quenching. The product after cold drawing and stress relieving achieved high yield strength values and showed an excellent toughness, even at – 40°C, in both the transverse and longitudinal directions.

scholarly journals Structure and Properties of High-Strength Ti Grade 4 Prepared by Severe Plastic Deformation and Subsequent Heat Treatment

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1116
Author(s):  
Alena Michalcová ◽  
Dalibor Vojtěch ◽  
Jaroslav Vavřík ◽  
Kristína Bartha ◽  
Přemysl Beran ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Strength ◽  
Ultimate Tensile Stress ◽  
Internal Stresses ◽  
In Situ Xrd ◽  
Microstructure Observation

Severe plastic deformation represented by three passes in Conform SPD and subsequent rotary swaging was applied on Ti grade 4. This process caused extreme strengthening of material, accompanied by reduction of ductility. Mechanical properties of such material were then tuned by a suitable heat treatment. Measurements of in situ electrical resistance, in situ XRD and hardness indicated the appropriate temperature to be 450 °C for the heat treatment required to obtain desired mechanical properties. The optimal duration of annealing was stated to be 3 h. As was verified by neutron diffraction, SEM and TEM microstructure observation, the material underwent recrystallization during this heat treatment. That was documented by changes of the grain shape and evaluation of crystallite size, as well as of the reduction of internal stresses. In annealed state, the yield stress and ultimate tensile stress decreased form 1205 to 871 MPa and 1224 to 950 MPa, respectively, while the ductility increased from 7.8% to 25.1%. This study also shows that mechanical properties of Ti grade 4 processed by continual industrially applicable process (Conform SPD) are comparable with those obtained by ECAP.

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