The coprecipitation of Cr3P and Cr in Cu

1988 ◽  
Vol 46 ◽  
pp. 764-765
Author(s):  
M.J. Witcomb ◽  
U. Dahmen ◽  
K.H. Westmacott
Keyword(s):  
Orientation Relationship ◽  
Interface Structure ◽  
Model System ◽  
Relative Orientation ◽  
Age Hardening ◽  
Precipitation Behavior ◽  
Solution Treated ◽  
Small Needle ◽  
Diffraction Patterns ◽  
Interface Structures

Cu-Cr age-hardening alloys are of interest as a model system for the investigation of fcc/bcc interface structures. Several past studies have investigated the morphology and interface structure of Cr precipitates in a Cu matrix (1-3) and good success has been achieved in understanding the crystallography and strain contrast of small needle-shaped precipitates. The present study investigates the effect of small amounts of phosphorous on the precipitation behavior of Cu-Cr alloys.The same Cu-0.3% Cr alloy as was used in earlier work was rolled to a thickness of 150 μm, solution treated in vacuum at 1050°C for 1h followed by quenching and annealing for various times at 820 and 863°C.Two laths and their corresponding diffraction patterns in an alloy aged 2h at 820°C are shown in correct relative orientation in Fig. 1. To within the limit of accuracy of the diffraction patterns the orientation relationship was that of Kurdjumov-Sachs (KS), i.e. parallel close-packed planes and directions.

The Effect of Pb on the Interface Structure of Fe/Cr(100) Metallic Multilayers

2000 ◽  
Vol 648 ◽  
Author(s):  
Kyu-Young Kim ◽  
Masao Kamiko ◽  
Sang-Mun Oh ◽  
Guang-Hong Lu ◽  
Ryoichi Yamamoto
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Interface Structure ◽  
Metallic Multilayers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Interface Structures

AbstractWe investigated the differences in the interface structures and magnetotransport properties between surfactant-mediated multilayers and normal ones. From the observations of RHEED and High-Resolution X-ray diffraction patterns, we confirmed that the surfaces of Fe/Cr(100) multilayers with Pb are flatter and the interfaces are sharper than one without Pb, which means that Pb operates as an effective surfactant. The magnetoresistance(MR) ratio of the multilayers prepared with Pb was larger than that of the multilayers prepared without Pb. The change of resistance with magnetic field was larger for the multilayers with a surfactant.

Precipitation in Al-Li-Cu Alloys

1981 ◽  
Vol 39 ◽  
pp. 44-45
Author(s):  
J. E. O'Neal ◽  
K. K. Sankaran
Keyword(s):  
Electron Microscopy ◽  
Age Hardening ◽  
Precipitation Behavior ◽  
Zone Formation ◽  
Specific Strength ◽  
Hardening Behavior ◽  
Cu Alloys ◽  
High Specific Strength ◽  
Transmission Electron ◽  
Structural Applications

Al-Li-Cu alloys combine high specific strength and high specific modulus and are potential candidates for aircraft structural applications. As part of an effort to optimize Al-Li-Cu alloys for specific applications, precipitation in these alloys was studied for a range of compositions, and the mechanical behavior was correlated with the microstructures.Alloys with nominal compositions of Al-4Cu-2Li-0.2Zr, Al-2.5Cu-2.5Li-0.2Zr, and Al-l.5Cu-2.5Li-0.5Mn were argon-atomized into powder at solidification rates ≈ 103°C/s. Powders were consolidated into bar stock by vacuum pressing and extruding at 400°C. Alloy specimens were solution annealed at 530°C and aged at temperatures up to 250°C, and the resultant precipitation was studied by transmission electron microscopy (TEM).The low-temperature (≲100°C) precipitation behavior of the Al-4Cu-2Li-0.2Zr alloy is a combination of the separate precipitation behaviors of Al-Cu and Al-Li alloys. The age-hardening behavior at these temperatures is characteristic of Guinier-Preston (GP) zone formation, with additional strengthening resulting from the coherent precipitation of δ’ (Al3Li, Ll2 structure), the presence of which is revealed by the selected-area diffraction pattern (SADP) shown in Figure la.

Precipitation in Al + 4% Cu Epitaxial Films

1968 ◽  
Vol 26 ◽  
pp. 384-385
Author(s):  
S. Herd ◽  
S. M. Mader
Keyword(s):  
Solid Solution ◽  
Bulk Material ◽  
Epitaxial Films ◽  
Detectable Change ◽  
Cu Films ◽  
Solution Treated ◽  
Single Crystal Films ◽  
Crystal Films ◽  
Diffraction Patterns ◽  
Deposited Films

Single crystal films in (001) orientation, about 1500 Å thick, were produced by R-F sputtering of Al + 4 wt % Cu onto cleaved KCl at 150°C substrate temperature. The as-deposited films contained numerous θ-CuAl2 particles (C16 structure) about 0.1μ in size. They were transferred onto Mo screens, solution treated and rapidly cooled (within about ½ min) so as to retain a homogeneous solid solution. Subsequently, the films were aged in vacuum at various temperatures in order to induce precipitation and to compare structures and morphologies of precipitate particles in Al-Cu films with those found in age hardened bulk material.Aging for 3 weeks at 60°C or 48 hrs at 100°C did not produce any detectable change in high resolution micrographs or diffraction patterns. In this range Guinier-Preston zones (GP) form in quenched bulk material. The absence of GP in the present experiments in this aging range is perhaps due to the cooling rate employed, which might be more equivalent to an aged and reverted bulk material than to a quenched one.

Moire Fringes on Precipitates in Quenched and Aged Beryllium

1968 ◽  
Vol 26 ◽  
pp. 426-427
Author(s):  
F. J. Fraikor ◽  
A. W. Brewer
Keyword(s):  
Ternary Phase ◽  
Volume Fraction ◽  
Age Hardening ◽  
Orientation Relationships ◽  
Solute Content ◽  
Moiré Fringes ◽  
Moire Patterns ◽  
Total Volume Fraction ◽  
Diffraction Patterns ◽  
Moiré Patterns

A number of investigators have examined moire patterns on precipitate particles in various age-hardening alloys. For example, Phillips has analyzed moire fringes at cobalt precipitates in copper and Von Heimendahl has reported on moire fringes in the system Al-Au. Recently, we have observed moire patterns on impurity precipitates in beryllium quenched in brine from 1000°C and aged at various temperatures in the range of 500-800°C. This heat treatment of beryllium rolled from vacuum cast ingots produces the precipitation of both an fee ternary phase, AlFeBe4, and an hcp binary phase, FeBe11. However, unlike a typical age-hardening alloy, the solute content of this material is low (less than 1000 ppm of Fe and 600 ppm of Al) and hence the total volume fraction of precipitates is small. Therefore there is some difficulty in distinguishing the precipitates and their orientation relationships with the beryllium matrix since the weak precipitate spots generally do not appear on the diffraction patterns.

Effects of T6 Age Hardening on Microstructure and Mechanical Properties of Al-Si-Cu Cast Aluminium Alloy

2013 ◽  
Vol 770 ◽  
pp. 88-91
Author(s):  
Amporn Wiengmoon ◽  
Pattama Apichai ◽  
John T.H. Pearce ◽  
Torranin Chairuangsri
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Aging Time ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Hot Water ◽  
Age Hardening ◽  
Solution Treated ◽  
Cast Condition

Effects of T6 artificial aging heat treatment on microstructure, microhardness and ultimate tensile strength of Al-4.93 wt% Si-3.47 wt% Cu alloy were investigated. The T6 age hardening treatment consists of solution treatment at 500±5°C for 8 hours followed by quenching into hot water at 80°C and artificial aging at 150, 170, 200 and 230°C for 1-48 hours followed by quenching into hot water. Microstructure was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). XRD and SEM revealed that the microstructure in the as-cast condition consists of primary dendritic α-Al, acicular-plate and globular forms of eutectic Si and intermetallic phases including globular Al2Cu and a flake-shape Al5FeSi. By T6 aging hardening, some intermetallics were dissolved and spheroidized. The volume fraction of eutectic phases in the as-cast, solution-treated, and solution-treated plus aging at 170°C for 24 hours is 17%, 12% and 10%, respectively. TEM results showed that precipitates in under-aging condition at 170° C for 6 hours are in the form of disc shape with the diameter in the range of 7-20 nm. At peak aging at 170°C for 24 hours, thin-plate precipitates with about 3-10 nm in thickness and 20-100 nm in length were found, lengthening to about 30-200 nm at longer aging time. The microhardness and ultimate tensile strength were increased from 71 HV0.05 and 227 MPa in the as-cast condition up to 140 HV0.05 and 400 MPa after solution treatment plus aging at 170°C for 24 hours, and decreased at prolong aging time.

Effect of Ag addition on the age hardening and precipitation behavior in an Al-Cu-Li-Mg-Zn-Mn-Zr alloy

2020 ◽  
Vol 162 ◽  
pp. 110184
Author(s):  
Bo Jiang ◽  
Haisheng Wang ◽  
Danqing Yi ◽  
Yu Tian ◽  
Fanghua Shen ◽  
...  
Keyword(s):  
Age Hardening ◽  
Precipitation Behavior ◽  
Ag Addition ◽  
Zr Alloy

Effects of Oxygen and Nitrogen Addition on Phase Transformation in Ti-10at%V

2020 ◽  
Vol 985 ◽  
pp. 80-85
Author(s):  
Sengo Kobayashi ◽  
Ryohei Fukushima ◽  
Siqi Wu ◽  
Satoshi Okano
Keyword(s):  
Titanium Alloys ◽  
Spinodal Decomposition ◽  
Nitrogen Addition ◽  
Age Hardening ◽  
Solid Solution Strengthening ◽  
Iced Brine ◽  
Arc Melting ◽  
Solution Treated ◽  
Oxygen Addition ◽  
Effect Of Oxygen

The addition of oxygen or nitrogen in titanium alloys increases the hardness by the solid solution strengthening. Spinodal decomposition in titanium alloys is also the way to increase the hardness. This study aimed to reveal the effect of oxygen or nitrogen addition on spinodal decomposition in Ti-10at%V. Ti-10at%V-(0, 1, 3)at%O or N alloys were prepared by arc-melting. They were solution-treated at 1200 or 1300 °C for 0.6 ks and then quenched in iced brine. The solution treated specimens were aged at 375 °C. The increase of hardness was decreased by the oxygen or nitrogen addition in the alloys. The addition of nitrogen more suppressed the age-hardening than the case of oxygen addition. The modulated structure caused by spinodal decomposition in the laths was observed in all the aged specimens. The wavelength of spinodal decomposition of the aged specimens increased with the addition of oxygen or nitrogen, leading to a decrease in age-hardening by spinodal decomposition.

Characterization of the Ni/NiO, Interface Region in Oxidized High Purity Nickel by Transmission Electron Microscopy

1985 ◽  
Vol 48 ◽  
Author(s):  
Howard T. Sawhill ◽  
Linn W. Hobbs
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Purity ◽  
Structure Factor ◽  
Dihedral Angles ◽  
Interfacial Energies ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Interface Structures

ABSTRACTNi/NiO interface structures were investigated using TEM, and the observed structures were compared with current heterophase interface models. Relative magnitudes of Ni/NiO interfacial energies were obtained from measurements of dihedral angles at triple grain junctions between Ni and NiO grains. Extra reflections in diffraction patterns from oxide grains adjacent to the Ni/NiO interface were compared with kinematical structure factor calculations for several proposed structures.

(111)p microtwinning in SrRuO3 thin films on (001)p LaAlO3

2009 ◽  
Vol 65 (6) ◽  
pp. 694-698 ◽  
Author(s):  
Y. Han ◽  
I. M. Reaney ◽  
D. S. Tinberg ◽  
S. Trolier-McKinstry
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Orientation Relationship ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Zone Axis ◽  
Laser Deposition ◽  
Transmission Electron ◽  
Diffraction Patterns

SrRuO3 (SRO) thin films grown on (001)p (p = pseudocubic) oriented LaAlO3 (LAO) by pulsed laser deposition have been characterized using transmission electron microscopy. Observations along the 〈100〉p directions suggests that although the SRO layer maintains a pseudocube-to-pseudocube orientation relationship with the underlying LAO substrate, it has a ferroelastic domain structure associated with a transformation on cooling to room temperature to an orthorhombic Pbnm phase (a − a − c + Glazer tilt system). In addition, extra diffraction spots located at ±1/6(ooo)p and ±1/3(ooo)p (where `o' indicates an index with an odd number) positions were obtained in 〈110〉p zone-axis diffraction patterns. These were attributed to the existence of high-density twins on {111}p pseudocubic planes within the SrRuO3 films rather than to more conventional mechanisms for the generation of superstructure reflections.

Sign in / Sign up

Export Citation Format

Share Document