Electrochemical Deposition of FeCo Alloys and FeCo/TiO2 Nanocomposites

2001 ◽  
Vol 674 ◽  
Author(s):  
I. Shao ◽  
P. M. Vereecken ◽  
R. C. Cammarata ◽  
P. C. Searson ◽  
C. L. Chien
Keyword(s):  
Electrochemical Deposition ◽  
High Stress ◽  
Oxide Dispersion Strengthened ◽  
Atomic Ratio ◽  
Knoop Hardness ◽  
Nanocomposite Films ◽  
Oxide Dispersion ◽  
High Quality ◽  
Deposition Parameters ◽  
Feco Alloys

ABSTRACTElectrochemical deposition of FeCo alloys with 1:1 atomic ratio has proved difficult due to cracking from high stress. By using a sulfamate electrolyte and optimizing other deposition parameters, we successfully electrodeposited high quality FeCo films of 20-25 mm in thickness and 7 mm in diameter. Using a suspension of hard oxide nanoparticles (25 nm TiO2) in the electrolyte, we produced oxide-dispersion-strengthened FeCo/TiO2 nanocomposite films with large grains. Enhanced strength was observed from these nanocomposites relative to pure FeCo alloys as determined from Knoop hardness measurements. In order to further improve the ductility of the alloys, vanadium has been codeposited with FeCo. Some preliminary results of FeCoV alloy deposition are reported.

Creep and Fracture Mechanisms in an Oxide-Dispersion Strengthened Ni3Al-Based Alloy Between 649°C and 982°C

1994 ◽  
Vol 364 ◽  
Author(s):  
Ralph P. Mason ◽  
Nicholas J. Grant
Keyword(s):  
Stress Exponent ◽  
High Stress ◽  
Oxide Dispersion Strengthened ◽  
Fracture Mechanisms ◽  
Oxide Dispersion ◽  
Creep Tests ◽  
Creep Mechanisms ◽  
Stress Region ◽  
Power Law Creep ◽  
Reported Data

AbstractAn oxide-dispersion strengthened (ODS) Ni3Al-based alloy has been fabricated and creep tested. Previously reported data for minimum creep rate as a function of stress indicated that two creep mechanisms operate at intermediate temperatures of 732 and 816°C [1]. This paper reports the results of recent interrupted creep tests and fractographic studies which serve to identify the two creep mechanisms. Creep at low stresses or low creep-rates occurs by constrained growth of cavities on transverse grain boundaries. In this low stress region an apparent stress exponent of 5.1 is observed. Creep at high stresses or high creep-rates results from the bulk deformation of grains by power law creep with a much smaller contribution due to grain boundary cavitation. The stress exponents of 13 and 22 observed in this high stress region are typical of ODS alloys. In both regions fracture is observed to be mixed mode with a large transgranular component due to the high grain aspect ratio developed in this material. Limited data at 982°C indicate the occurrence of only one mechanism which can be described by a stress exponent of 9.1. It was not possible, based on fractographic studies, to associate the creep mechanism at 982°C with either of those observed at the intermediate temperatures. No fractographic studies were performed at 649°C due to lack of valid specimens; however, the stress exponent of 13.5 observed at 649°C suggests that creep occurs by deformation of the grains.

Effect of Y/Ti atomic ratio on microstructure of oxide dispersion strengthened alloys

2017 ◽  
Vol 134 ◽  
pp. 35-40 ◽  
Author(s):  
Chenyang Lu ◽  
Zheng Lu ◽  
Rui Xie ◽  
Zhengyuan Li ◽  
Chunming Liu ◽  
...  
Keyword(s):  
Oxide Dispersion Strengthened ◽  
Atomic Ratio ◽  
Oxide Dispersion

Fine Microstructure of a Mechanically Alloyed Oxide Dispersion Strengthened Nickel-Base Superalloy

1977 ◽  
Vol 35 ◽  
pp. 298-299
Author(s):  
Jordi Marti ◽  
Timothy E. Howson ◽  
David Kratz ◽  
John K. Tien
Keyword(s):  
Solid Solution ◽  
Volume Fraction ◽  
Stress Rupture ◽  
Oxide Dispersion Strengthened ◽  
Solid Solution Alloy ◽  
Oxide Dispersion ◽  
Creep And Stress Rupture ◽  
Mechanically Alloyed ◽  
Fine Microstructure ◽  
Nickel Base

The previous paper briefly described the fine microstructure of a mechanically alloyed oxide dispersion strengthened nickel-base solid solution. This note examines the fine microstructure of another mechanically alloyed system. This alloy differs from the one described previously in that it is more generously endowed with coherent precipitate γ forming elements A1 and Ti and it contains a higher volume fraction of the finely dispersed Y2O3 oxide. An interesting question to answer in the comparative study of the creep and stress rupture of these two ODS systems is the role of the precipitate γ' in the mechanisms of creep and stress rupture in alloys already containing oxide dispersoids.The nominal chemical composition of this alloy is Ni - 20%Cr - 2.5%Ti - 1.5% A1 - 1.3%Y203 by weight. The system receives a three stage heat treatment-- the first designed to produce a coarse grain structure similar to the solid solution alloy but with a smaller grain aspect ratio of about ten.

Oxide dispersion-strengthened silver: manufacturing and properties

2003 ◽  
Vol 94 (5) ◽  
pp. 587-592 ◽  
Author(s):  
Uta Grundmann ◽  
Martin Heilmaier ◽  
Ulrich Martin ◽  
Heinrich Oettel ◽  
Ludwig Schultz
Keyword(s):  
Oxide Dispersion Strengthened ◽  
Oxide Dispersion

scholarly journals ODS EUROFER Steel Strengthened by Y-(Ce, Hf, La, Sc, and Zr) Complex Oxides

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1148 ◽  
Author(s):  
Roman Husák ◽  
Hynek Hadraba ◽  
Zdeněk Chlup ◽  
Milan Heczko ◽  
Tomáš Kruml ◽  
...  
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Complex Oxides ◽  
Oxide Dispersion Strengthened ◽  
Interparticle Spacing ◽  
Oxide Dispersion ◽  
Strengthening Effect ◽  
Dispersion Strengthening ◽  
Doping Element ◽  
Average Grain Size

Oxide dispersion-strengthened (ODS) materials contain homogeneous dispersions of temperature-stable nano-oxides serving as obstacles for dislocations and further pinning of grain boundaries. The strategy for dispersion strengthening based on complex oxides (Y-Hf, -Zr, -Ce, -La) was developed in order to refine oxide dispersion to enhance the dispersion strengthening effect. In this work, the strengthening of EUROFER steel by complex oxides based on Y and elements of the IIIB group (lanthanum, scandium) and IVB group (cerium, hafnium, zirconium) was explored. Interparticle spacing as a dispersoid characteristic appeared to be an important factor in controlling the dispersion strengthening contribution to the yield strength of ODS EUROFER steels. The dispersoid size and average grain size of ODS EUROFER steel were altered in the ranges of 5–13 nm and 0.6–1.7 µm, respectively. Using this strategy, the yield strength of the prepared alloys varied between 550 MPa and 950 MPa depending on the doping element.

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