Effect of included oxide films on the structure of the Beilby layer

1952 ◽  
Vol 212 (1111) ◽  
pp. 458-459 ◽  
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
High Temperatures ◽  
Oxide Films ◽  
Subsequent Annealing ◽  
Surface Layers ◽  
Fine Grain ◽  
Oxide Particles ◽  
Considerable Depth

Experiments show that during repeated sliding, oxide is included to a considerable depth beneath the surface of the metal. Subsequent annealing at high temperatures shows that the included oxide particles prevent grain growth in the surface layers. This process may be largely responsible for the fine grain size of the Beilby layer.

Microstructure and Tensile Properties of Hot Worked High Nb Containing TiAl Alloy on Industrial Scale

2005 ◽  
Vol 475-479 ◽  
pp. 785-788
Author(s):  
Jun Pin Lin ◽  
Xiang Jun Xu ◽  
Jian Feng Gao ◽  
Yan Li Wang ◽  
Zhi Lin ◽  
...  
Keyword(s):  
Grain Size ◽  
Tensile Properties ◽  
High Temperatures ◽  
Tial Alloy ◽  
Hot Working ◽  
Industrial Scale ◽  
Initial Microstructure ◽  
Similar Composition ◽  
Fine Grain ◽  
Good Workability

. A hot working and its effect on the microstructure and tensile properties of Ti-45Al-9 (Nb, W, B, Y) alloy ingot on industrial scale were investigated. The results showed that the alloy has good workability in anα+γphase region. An ingot on industrial scale was successfully extruded followed by multi-step canned forging. The initial microstructure of the alloy is fine full lamellar (FL) microstructure. After hot working a sound pancake exhibiting a fine grain duplex (DP) microstructure with grain size about 20μm was obtained. The as-forged alloy has more balanced tensile properties than the small heats with similar composition and microstructure at both room and high temperatures.

Effect of grain size of sputtered cerium‐oxide films on their electrical and kinetic behavior at high temperatures

1994 ◽  
Vol 75 (8) ◽  
pp. 3991-3999 ◽  
Author(s):  
Werner Lohwasser ◽  
Josef Gerblinger ◽  
Uwe Lampe ◽  
Hans Meixner
Keyword(s):  
Grain Size ◽  
Cerium Oxide ◽  
High Temperatures ◽  
Oxide Films ◽  
Kinetic Behavior

Development of Grain Structure and Texture during Annealing in Asymmetrically Rolled AA5754

2004 ◽  
Vol 467-470 ◽  
pp. 381-386 ◽  
Author(s):  
Hai Ou Jin ◽  
David J. Lloyd
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Annealing Temperature ◽  
Rolling Texture ◽  
Deformation Texture ◽  
Grain Structure ◽  
Asymmetric Rolling ◽  
Fine Grain ◽  
Continuous Recrystallization ◽  
Cold Rolling Texture

AA5754 sheet has been processed by asymmetric rolling and the development of grain structure and texture in subsequent annealing studied at 240-500°C. It has been found that asymmetric rolling facilitates the formation of ultra-fine grain structure (1-2µm grain size) by shear strain promoted continuous recrystallization, which is a process of extended recovery and subgrain/grain growth. The ultra-fine grain structure is not thermally stable, and when the annealing temperature or time increases, the grain size eventually grows to its Zener limit. The deformation texture is similar to the typical f.c.c. cold rolling texture but rotated about the transverse direction. Along with the formation of an ultra-fine grain structure and subsequent grain growth, the deformation texture is retained.

Effects of AlN Particles and Electromagnetic Stirring on As-Cast Structure of AZ31 Alloys

2011 ◽  
Vol 675-677 ◽  
pp. 771-774 ◽  
Author(s):  
Song Wei Gu ◽  
Hai Hao ◽  
Can Feng Fang ◽  
Shou Hua Ji ◽  
Xing Guo Zhang
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Grain Growth ◽  
Magnesium Alloys ◽  
Electromagnetic Stirring ◽  
Grain Refiner ◽  
Cast Structure ◽  
Fine Grain ◽  
Refinement Mechanism

A fine grain size generally leads to improved structural uniformity of magnesium alloys. AlN has been identified as a potential grain refiner and electromagnetic stirring may have great effects on microstructure and grain growth. This study will be focused on the effects of AlN particles and electromagnetic stirring on the as-cast structure of AZ31 alloys.The grain refinement mechanism of both methods on magnesium alloy and their interaction effects are also discussed.

Grain Growth, Microstructure and Property of Ultrafine WC-Co Alloy by Spark Plasma Sintering

2007 ◽  
Vol 558-559 ◽  
pp. 959-963 ◽  
Author(s):  
Lan Sun ◽  
Cheng Chang Jia ◽  
Min Xian ◽  
Rui Jun Cao
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Abnormal Grain Growth ◽  
Full Density ◽  
Fine Grain ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Increasing Temperature ◽  
New Phase

In order to control WC grain size and get a microstructure with fine grain size during the sintering process, WC grain growth in WC-Co cemented carbide was investigated. The possible reason on the grain growth was showed which includes the normal grain growth (NGG) and the abnormal grain growth (AGG). We adopted the SPS (spark plasma sintering) to sinter nanometer WC-Co powder, the range of temperature was 1100 -1250 °C, the pressure was 40MPa, and sintering time was 5min. In this paper, we discuss the density, hardness, microstructures and grain sizes of the sintered samples. The results showed that during the process sintering WC-Co powder, there are two kinds of growths. XRD investigation of the WC–Co samples spark plasma sintered to full density revealed that no new phase was created. Through the observed microstructure of the sintered samples, we analyzed the reason of the abnormal grain growth of WC grain. The density and hardness of samples were increased with increasing temperature.

Grain Growth, Stress, and Impurities in Electroplated Copper

2002 ◽  
Vol 17 (3) ◽  
pp. 582-589 ◽  
Author(s):  
S. H. Brongersma ◽  
E. Kerr ◽  
I. Vervoort ◽  
A. Saerens ◽  
K. Maex
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Growth ◽  
Sheet Resistance ◽  
Grain Size Distribution ◽  
High Temperatures ◽  
Intermediate State ◽  
Growth Stress ◽  
Grain Structure ◽  
Electroplated Copper

The widely observed secondary grain growth in electroplated Copper layers is shown to be incomplete after the sheet resistance and stress of the layer appear to have stabilized. Instead the layer is in an intermediate state with a grain size distribution that depends on the plating conditions. Further extensive annealing at high temperatures results in an additional considerable enlargement of the grain structure, accompanied by an additional decrease of the sheet resistance and desorption of impurities that were incorporated during plating.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

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