Composition Segregation of Ge-Rich GST and Its Effect on Reliability

2021 ◽  
Author(s):  
Yung-Huei Lee ◽  
P.J. Liao ◽  
Vincent Hou ◽  
Dawei Heh ◽  
Chih-Hung Nien ◽  
...  
Keyword(s):  
Composition Segregation

scholarly journals Reaction products of Sm2Zr2O7 with calcium-magnesium-aluminum-silicate (CMAS) and their evolution

2021 ◽  
Author(s):  
Yinghua Wang ◽  
Zhuang Ma ◽  
Ling Liu ◽  
Yanbo Liu
Keyword(s):  
Solid Solution ◽  
Aluminum Silicate ◽  
Thermal Barrier ◽  
Reaction Products ◽  
Barrier Coatings ◽  
Magnesium Aluminum Silicate ◽  
Composition Segregation ◽  
Calcium Magnesium ◽  
New Generation ◽  
Sand Dust

AbstractDuring flight, many silicates (sand, dust, debris, fly ash, etc.) are ingested by an engine. They melt at high operating temperatures on the surface of thermal barrier coatings (TBCs) to form calcium-magnesium-aluminum-silicate (CMAS) amorphous settling. CMAS corrodes TBCs and causes many problems, such as composition segregation, degradation, cracking, and disbanding. As a new generation of TBC candidate materials, rare-earth zirconates (such as Sm2Zr2O7) have good CMAS resistance properties. The reaction products of Sm2Zr2O7 and CMAS and their subsequent changes were studied by the reaction of Sm2Zr2O7 and excess CMAS at 1350 °C. After 1 h of reaction, Sm2Zr2O7 powders were not completely corroded. The reaction products were Sm-apatite and c-ZrO2 solid solution. After 4 h of reaction, all Sm2Zr2O7 powders were completely corroded. After 24 h of reaction, Sm-apatite disappeared, and the c-ZrO2 solid solution remained.

Application Research of a New Coupling Stirring on DC Casting Process for Large-Sized Aluminum Ingots

2015 ◽  
Vol 817 ◽  
pp. 48-54 ◽  
Author(s):  
Hai Jun Wang ◽  
Jun Xu ◽  
Zhi Feng Zhang ◽  
Bo Liang ◽  
Ming Wei Gao
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Casting Process ◽  
Direct Chill ◽  
Application Research ◽  
Center Position ◽  
Composition Segregation ◽  
Dc Casting ◽  
The Difference ◽  
7075 Alloy

A new coupling stirring technology was proposed and used to prepare direct chill (DC) ingots. Ingots of 7075 alloy were produced by a process of normal direct chill (NDC) casting and coupling-stirring direct chill (CDC) casting, respectively. The effect of the technology on the microstructures, composition segregation and mechanical properties of the ingots was investigated. The results showed that the temperature variation in the CDC casting process was more uniform than that in the NDC casting process. The grain of the CDC ingots was finer and more spherical than the grain of NDC ingots. The grain size at the edge, 1/2 radius, and center position in CDC ingot decrease by 28%, 22%, and 24% comparing with the grain size of the corresponding positions of NDC ingot, respectively. The billets with higher performance and lower macro-segregation were obtained in case of CDC. The flow stresses and the difference in different positions of DC ingots measured at Gleeble-1500D thermo-mechanical simulator decreased obviously when the coupling stirring technology is used in the casting process.

The Technology Study of Steel Belt Feeding Machine of Crystallizer of Continuous Casting

2015 ◽  
Vol 727-728 ◽  
pp. 513-516
Author(s):  
Lin Hui Yu ◽  
Ming Gang Shen ◽  
Ji Dong Li ◽  
Yi Yong Wang ◽  
Jian Ming Su ◽  
...  
Keyword(s):  
Temperature Field ◽  
Continuous Casting ◽  
Casting Speed ◽  
Steel Strip ◽  
Technology Study ◽  
Melt Temperature ◽  
Casting Section ◽  
Composition Segregation ◽  
Feeding Speed ◽  
Feeding Technology

Crystallizer steel belt feeding technology make use of melt’s fusion decalescence, controlling the distribution of melt temperature field, restrain the columnar crystal’s growing to eliminate the composition segregation and internal loose of continuous casting. And it will improve the continuous casting’s quality. By discussing the effect of casting speed, the size of steel, casting section and other factors on the steel belt feeding speed, making comparison of different casting section get strip suitable feeding speed and range of strip size, combining with a steel for steel strip feeding test mold, its theoretical and practical production results the basic agreement

Effect of Pits in InGaN/GaN Multi-Quantum Wells on the Strain and In Composition Segregation

2000 ◽  
Vol 180 (1) ◽  
pp. 81-84 ◽  
Author(s):  
Z.J. Yang ◽  
Y.Z. Tong ◽  
G.Y. Zhang ◽  
X.L. Du ◽  
N. Fujii ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Composition Segregation

Study of Centerline Segregation in Alloy Tool Steel on CSP Technology

2011 ◽  
Vol 197-198 ◽  
pp. 1744-1748
Author(s):  
Jing Hu Chen ◽  
Xiao Hua Jie
Keyword(s):  
Carbon Content ◽  
Rolled Steel ◽  
Thin Slab ◽  
Steel Coil ◽  
Carbon Segregation ◽  
Negative Segregation ◽  
Alloy Tool ◽  
Composition Segregation ◽  
Positive Segregation ◽  
Columnar Grain

After studying the slab of the CSP, the composition segregation and the finished products, we drew the conclusion that the low magnification of CSP thin slab is denser, columnar grain more developed; Loose and segregation exist while the segregation is smaller than traditional one. From the surface to the center, obvious carbon segregation exists: nearby the center is negative segregation and in the center is positive segregation. With the increase of carbon content, carbon segregation also increases. The carbon content of tundish is different from that of rolled steel coil --namely, the carbon content of the rolled coil is significantly lower.

Influence of Solution Temperature on Compositions Segregation and Creep Behavior of a Single Crystal Nickel-Based Superalloy

2013 ◽  
Vol 747-748 ◽  
pp. 690-696 ◽  
Author(s):  
Su Gui Tian ◽  
Y.C. Xue ◽  
Z. Zeng
Keyword(s):  
Creep Resistance ◽  
Solution Treatment ◽  
Solution Temperature ◽  
Medium Temperature ◽  
Creep Properties ◽  
Nickel Based Superalloy ◽  
Microstructure Observation ◽  
Composition Segregation ◽  
Deformation Features ◽  
Different Temperatures

By means of solution treatment at various temperatures, creep properties measurement and microstructure observation, the effects of heat treatment on composition segregation and creep properties were investigated. Results show that the various segregation extents of the elements are displayed in the alloys solution treated at different temperatures, and the segregation extent of the elements is improved with the solution temperature elevated, which may obvious improve the creep resistance of the alloy. And no rafted structure of the γ phase is detected in the alloy during creep at medium temperature. The deformation features of the alloy during creep at medium temperature are that the slipping of dislocations is activated in the γ matrix channels, and dislocations shearing into the γ phase may be decomposed to form the configuration of partials + stacking faults, which may hinder the cross-slipping of the dislocations to improve the creep resistance of the alloy.

The Influence of Composition Segregation to the Microstructure and Mechanical Properties of SA508-3 Steel

2010 ◽  
Vol 146-147 ◽  
pp. 1017-1021 ◽  
Author(s):  
Lu Han Hao ◽  
Ming Yue Sun ◽  
Dian Zhong Li
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Strength Loss ◽  
Bottom Part ◽  
Microstructure And Mechanical Properties ◽  
Alloyed Cementite ◽  
Energy Dispersion Spectrum ◽  
Composition Segregation ◽  
The Matrix ◽  
Precipitated Phases

A large scale ingot was dissected to study the segregation law of the elements. The influence of composition segregation to the microstructure and mechanical properties of SA508-3 steel was studied by the comparison of three positions on the ingot. Two precipitated phases were approved to be alloyed cementite and molybdenum carbide (Mo2C). It has demonstrated that the middle and upper parts of the ingot were almost the same in compositions except for a slightly difference in the carbon content. The upper part with more carbon included has relatively more carbide precipitation after the performance heat treatment. The bottom part of the ingot has the lowest carbon and molybdenum content, while the reduction in the amount of precipitated carbide was not observed. On the contrary, fine needle-like Mo2C are extensively distributed in the matrix of the bottom part besides a variety of coarse cementite rods. And the data of Energy Dispersion Spectrum (EDS) mapping has suggested that precipitation of Mo2C tends to bring the segregation of impurities. Many large inclusions were found in the bottom part of the ingot, which were considered to be the main reason for the strength loss of this area.

scholarly journals Brass products in the coronet excavated from a M2-numbered Sui-Tang-dynasty tomb situated in Kun Lun Company in Xi'an, Shaanxi

2021 ◽  
Author(s):  
Yanbing Shao ◽  
Fengrui Jiang ◽  
Jingnan Du ◽  
Junchang Yang ◽  
Quanmin Zhang
Keyword(s):  
Tang Dynasty ◽  
Hot Forging ◽  
Metallographic Analysis ◽  
Historical Period ◽  
Central Plains ◽  
Second Stage ◽  
Feudal Society ◽  
Composition Segregation ◽  
Tangible Evidence ◽  
Selection Of

Abstract In this study, the brass wires in the coronet excavated from M2 tomb in Xi'an, Shaanxi, dating back to Sui-Tang-dynasty were probed via portable X-ray fluorescence spectrometry (XRF) and scanning electron microscopy in combination with energy dispersive spectrometry (SEM-EDS) techniques. The wires were found to be composed of 83 wt% of copper, 12 wt% of zinc, and 3 wt% of tin. According to the metallographic analysis, the wires were formed by integral hot forging, and were then installed on the coronet after surface cold shaping, via cutting and hammering during the production of the support parts. It indicated that the composition of brass was evenly distributed without obvious composition segregation, revealing the features of the second stage of brass smelting in ancient China, which may prove brass had appeared and brass smelting technology had been mastered in the Sui-Tang-dynasty in the Central Plains of China. In addition, the use of brass in the coronet was in accorded with the hierarchical symbol given to the material by the feudal society. And the selection of brass was based on the dual combination of the excellent mechanical properties and the golden surface of brass. Thus, brass in the Sui-Tang-dynasty historical period was the tangible evidence of the development level of metallurgical technology, and also reflected the artistic and social attributes given to materials by different stages of social development.

scholarly journals Interface-Driven Structural Distortions and Composition Segregation in Two-Dimensional Heterostructures

2017 ◽  
Vol 56 (46) ◽  
pp. 14448-14452 ◽  
Author(s):  
Jeffrey Ditto ◽  
Devin R. Merrill ◽  
Gavin Mitchson ◽  
Joshua J. Gabriel ◽  
Kiran Mathew ◽  
...  
Keyword(s):  
Two Dimensional ◽  
Structural Distortions ◽  
Composition Segregation
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