Nano-lamellar Structures in a Rolled Cu-Ag Alloy

2001 ◽  
Vol 683 ◽  
Author(s):  
Mark T. Lyttle ◽  
D.A. Hughes
Keyword(s):  
Early Development ◽  
Microstructural Evolution ◽  
Preferred Orientation ◽  
Texture Development ◽  
High Angle ◽  
Directionally Solidified ◽  
Lamellar Structures ◽  
Single Region ◽  
Rapid Divergence ◽  
The Individual

ABSTRACTThe microstructural evolution and texture development in a Cu-Ag eutectic during rolling are systematically investigated. A directionally solidified Cu-Ag alloy with a single dominant texture is deformed to several rolling reductions. At each of these strains, the microstructure and texture are characterized. Rapid divergence of local crystal orientations leads to the early development of high-angle Cu-Ag boundary/interface orientations, while less misorientation accumulation occurs within the individual copper and silver layers. With increasing deformation, orientations of the copper and silver phases in a single region are observed to diverge to two distinct textures, and within each of the single phases, there is a greater spread of orientations of individual cells while still retaining an identifiable preferred orientation.

MICROSTRUCTURAL EVOLUTION OF DIRECTIONALLY SOLIDIFIED Ni--BASED SUPERALLOY DZ125 UNDER PLANAR GROWTH

2010 ◽  
Vol 46 (9) ◽  
pp. 1075-1080 ◽  
Author(s):  
Zhixian MIN ◽  
Jun SHEN ◽  
Lingshui WANG ◽  
Zhourong FENG ◽  
Lin LIU ◽  
...  
Keyword(s):  
Microstructural Evolution ◽  
Directionally Solidified ◽  
Planar Growth

Directive Guidance as a Cultural Practice for Learning by Chinese-Heritage Babies

2021 ◽  
pp. 1-18
Author(s):  
Yu Zhang ◽  
Su-hua Wang ◽  
Shinchieh Duh
Keyword(s):  
Empirical Study ◽  
Early Development ◽  
Filial Piety ◽  
Theoretical Framework ◽  
Cultural Practice ◽  
European American ◽  
Individual Level ◽  
Children’S Learning ◽  
The Usa ◽  
The Individual

We provide a framework of analysis for Chinese ways of learning that extends beyond the individual level. The theoretical framework focuses on Confucian principles of <i>xiào</i> (孝, filial piety), <i>guăn</i> (管, to govern), and <i>dào dé guān</i> (道德觀, virtues), which leads us to argue that directive guidance as a cultural practice nourishes Chinese-heritage children’s learning as early as in infancy. To illustrate how directive guidance occurs in action for infants, we present an empirical study that examined the interaction of mother-infant dyads in Taipei, Taiwan, when they played with a challenging toy. The dyads co-enacted directive guidance more frequently than their European-American counterparts in the USA – through hand holding, intervening, and collaboration – while infants actively participate in the practice. We discuss the early development of strengths for learning that is fostered through culturally meaningful practices recurrent in parent-infant interaction.

Influence of Cooling Speed on the Microstructure of Particles Reinforced 7055Al Composites Subject to Regulatory Cryogenic Treatment

2014 ◽  
Vol 941-944 ◽  
pp. 314-317
Author(s):  
Guirong Li ◽  
Hong Ming Wang ◽  
Yu Hua Cui ◽  
Yue Ming Li ◽  
Cong Xiang Peng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Dislocation Density ◽  
Microstructural Evolution ◽  
Cryogenic Treatment ◽  
Preferred Orientation ◽  
Electronic Microscopy ◽  
Transmission Electronic Microscopy ◽  
Cooling Speed

Al3Ti and Al3Zr particles reinforced 7055Al composites were processed by cryogenic treatment with different cooling speed at 1°C/min, 3°C/min and 5°C/min. Transmission Electronic Microscopy (TEM) was mainly used to analyze the microstructural evolution of the treated samples. The results show that with the increase of cooling speed the precipitate amount and dislocation density have been increased. The precipitates orientation exhibits some preferred orientation. The mechanical properties test demonstrates that for the samples treated at 5°C/min the tensile strength and elongation has arrived at the utmost.

scholarly journals Image Simulations of Ge Twin Boundaries.

1992 ◽  
Vol 295 ◽  
Author(s):  
Stuart Mckernan ◽  
C. Barry Carter
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
High Angle ◽  
Structural Units ◽  
Twin Boundaries ◽  
Large Unit ◽  
Unit Cells ◽  
The Individual ◽  
Image Simulations

AbstractGeneral high-angle tilt grain boundaries may be described by an arrangement of repeating structural units. Some grain-boundary defects may also be modeled by the incorporation of structural units of related boundary structures into the boundary. The simulation of these structures requires the use of prohibitively large unit cells. The possibility of modeling these boundaries by the superposition of image simulations of the individual structural units isinvestigated.

The fabric of the granulites of Mont Tremblant Park, Quebec

1968 ◽  
Vol 5 (4) ◽  
pp. 801-812 ◽  
Author(s):  
Michael Katz
Keyword(s):  
Relevant Literature ◽  
Granulite Facies ◽  
Sensu Stricto ◽  
Preferred Orientation ◽  
Experimental Investigations ◽  
Deformation Bands ◽  
Progressive Deformation ◽  
Mechanical Twins ◽  
The Individual

The fabric of the highly deformed and recrystallized gneisses formed under granulite facies conditions of metamorphism are described from Mont Tremblant Park, Quebec, Canada. These gneisses are termed granulites and are classified into quartzofeldspathic and hypersthene varieties.The term 'cataclastic-gneissose' fabrics is used to imply varying degrees of deformation and recrystallization without micro-brecciation or cataclasis 'sensu stricto' and a classification of these various fabrics is presented. The modifications in these granulites are progressive and are assumed to have the following sequence:[Formula: see text]During the evolution from mortar to granoblastic types, the minerals become flattened and increasingly elongated, while the individual recrystallized grains increase in size. The same deformation produced flaser and granoblastic gneisses in the quartzofeldspathic granulites and mortar and augen gneisses in the hypersthene granulites.The mineral relicts (porphyroclasts) in the mortar and augen gneisses are highly deformed and display evidence of strain, such as undulatory extinction, deformation bands, polygonization, mechanical twins, and bent cleavages. These mortar and augen gneisses display a poor preferred orientation of quartz c axis.In the recrystallized rocks the grains form a clear, fresh, unstrained polygonal mosaic and in the case of quartz, long leaf-like uniform plates are produced. In the flaser and especially the granoblastic gneisses no signs of strain remain and the recrystallized fabric consists of quartz plates alternating on a micro-scale with bands of polygonal fresh feldspar and granular streaks of dark minerals. A petrofabric diagram from a granoblastic gneiss shows a marked preferred orientation of quartz c axis.A review of the relevant literature on the natural and experimental investigations strongly supports the hypothesis that the fabrics of the granulites are produced as a result of the progressive deformation and recrystallization of the mineral constituents.

Effect of Elements on Hot Tearing of Directionally Solidified Ni-Based Superalloys

2010 ◽  
Vol 150-151 ◽  
pp. 975-978
Author(s):  
Yan Li Wang ◽  
Zhao Hui Huang ◽  
Xi Hong Zhao ◽  
Jia Rong Li
Keyword(s):  
Directional Solidification ◽  
Microstructural Evolution ◽  
Hot Tearing ◽  
Directionally Solidified ◽  
Al Content ◽  
Hot Tearing Susceptibility

The effect of elements such as Ti, Al, Hf, Zr and B on hot tearing susceptibility during directional solidification was explored by tube-like samples with thickness of 1.0 mm, 1.5mm and 2.0mm in wall. Results of SEM of elements on solidification of casting Ni-based superalloys were presented. The influential extent among the investigated elements is found to be: the largest is Ti, then Zr, B and Al, and Hf is the smallest. Titanium promotes the formation of (γ+γ´) eutectic, increases sizes of the eutectic. Increasing Al content results in the size of γ+γ´ eutectic and the number of γ´. Increasing Zr content promotes γ+γ´ eutectic.Varying B content shows little microstructural evolution.

The Creep Deformation and Elevated Temperature Microstructural Stability of a Two-Phase TiAl/Ti3Al Lamellar Alloy.

1994 ◽  
Vol 364 ◽  
Author(s):  
M. F. Bartholomeusz ◽  
J. A. Wert
Keyword(s):  
Elevated Temperature ◽  
Creep Rate ◽  
Microstructural Evolution ◽  
Creep Deformation ◽  
Minimum Creep Rate ◽  
Single Phase ◽  
Lamellar Microstructure ◽  
Microstructural Stability ◽  
Two Phase ◽  
The Individual

AbstractEnhanced work hardening of the phases in the lamellar microstructure has been cited as an explanation for the lower minimum creep rates of a two-phase TiAl/Ti3Al lamellar alloy compared with the minimum creep rates of the individual TiAl and Ti3Al single-phase alloys tested between 980 K and 1130 K. This proposition is confirmed by TEM observations. Thermal and thermomechanical exposure result in the microstructural evolution, which increases the minimum creep rate (εmin) of the lamellar alloy. The effect of microstructural evolution on εmin will be discussed in the present paper.

Microstructural evolution of a directionally solidified nickel-base superalloy during thermal fatigue

Rare Metals ◽  
2011 ◽  
Vol 30 (S1) ◽  
pp. 477-481 ◽  
Author(s):  
Pengcheng Xia ◽  
Lei Yang ◽  
Jinjiang Yu ◽  
Xiaofeng Sun ◽  
Hengrong Guan ◽  
...  
Keyword(s):  
Microstructural Evolution ◽  
Thermal Fatigue ◽  
Nickel Base Superalloy ◽  
Directionally Solidified ◽  
Nickel Base ◽  
Base Superalloy
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