HAYNES® 282™ Alloy: A New Wrought Superalloy Designed for Improved Creep Strength and Fabricability

2006 ◽  
Author(s):  
L. M. Pike
Keyword(s):  
Thermal Stability ◽  
Creep Strength ◽  
Volume Fraction ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Gamma Prime ◽  
Lower Volume Fraction ◽  
Structural Applications ◽  
Lower Volume ◽  
Prime Phase

A new wrought, gamma-prime strengthened superalloy, HAYNES 282 alloy, has been developed for high temperature structural applications, especially those in aero and land-based gas turbine engines. The new alloy possesses a unique combination of creep strength, thermal stability, and fabricability not found in currently available commercial alloys. The new alloy has excellent creep strength in the temperature range of 1200 to 1650°F (650 to 900°C), surpassing that of Waspaloy alloy and approaching that of R-41 alloy. This level of creep strength is realized despite the alloy having a significantly lower volume fraction of the strengthening gamma-prime phase. The lower gamma-prime content of the new alloy provides a considerable improvement in terms of fabricability and resistance to strain-age cracking, a problem often associated with this class of alloys. In this paper, the major characteristics and attributes of the new alloy including mechanical properties, oxidation resistance, thermal stability, and weldability are presented.

The Study on Microstructural and Optical Properties of Nanocrystalline Germanium Films

2010 ◽  
Vol 663-665 ◽  
pp. 324-327
Author(s):  
Chao Song ◽  
Rui Huang
Keyword(s):  
Multilayer Structure ◽  
Room Temperature ◽  
Multilayer Film ◽  
Volume Fraction ◽  
Raman Scattering Spectroscopy ◽  
Force Microscopy ◽  
Room Temperature Photoluminescence ◽  
Atomic Force ◽  
Lower Volume Fraction ◽  
Lower Volume

The germanium film and Ge/Si multilayer structure were fabricated by magnetron sputtering technique on silicon substrate at temperatures of 500°C. Raman scattering spectroscopy measurements reveal that the nanocrystalline Ge occurs in both kinds of samples. Furthermore, from the atomic force microscopy (AFM) results, it is found that the grain size as well as spatially ordering distribution of the nc-Ge can be modulated by the Ge/Si multilayer structure. The room temperature photoluminescence was also observed in the samples. However, compared with that from the nc-Ge film, the intensity of PL from the nc-Ge/a-Si multilayer film becomes weaker, which is attributed to its lower volume fraction of crystallized component.

scholarly journals An Experimental Validation Study of Ferrofluid Evaporation

2021 ◽  
Author(s):  
Wenjuan YU ◽  
Decai Li ◽  
Sifang Niu
Keyword(s):  
Base Fluid ◽  
Experimental Validation ◽  
Magnetic Particles ◽  
Evaporation Rate ◽  
Volume Fraction ◽  
Test Tube ◽  
Weight Losses ◽  
Lower Volume Fraction ◽  
Lower Volume ◽  
The Magnetic Field

Abstract Kerosene based ferrofluid was put into a test tube to evaporate under different conditions. The weight losses of samples were measured and the evaporation rates were calculated. The predictions of evaporation rates were made based on Bolotov’s model. It was found that the magnetic particles prevent the base fluid from evaporation and lower volume fraction leaded to higher evaporation rate. Bolotov’s model had a certain deviation but still well responsive to different variables. It was also found that the magnetic field made a difference to the evaporation rate.

Dielectric Behavior of Barium Titanate/Carbon Fibers Composites

2017 ◽  
Vol 898 ◽  
pp. 2101-2106
Author(s):  
Zhong Yang Wang ◽  
Xin Yan Li ◽  
Run Hua Fan ◽  
Pei Tao Xie ◽  
Kai Sun ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Barium Titanate ◽  
Carbon Fibers ◽  
Percolation Theory ◽  
High Dielectric Constant ◽  
Volume Fraction ◽  
Dielectric Behavior ◽  
Lower Volume Fraction ◽  
Lower Volume ◽  
High Dielectric

Conductor–insulator composites have been extensive researched for high dielectric constant. Most of them concentrated on metal polymers or metal ceramics. Barium titanate–carbon fibers composites were prepared by using a solid state reaction process with carbon fibers contents ranging from7 vol% to 23 vol%. Due to the high-aspect-ratio of carbon fiber, it was easy to produce a conducting network at much lower volume fraction. FESEM images illustrated that the carbon fibers influenced the densification and microstructure of the ceramics. Besides, addition of carbon fibers led to increase in dielectric permittivity, also had effects on the dielectric loss and ac conductivity. The dielectric and conductivity properties as a function of carbon fibers volume fraction were explained by the percolation theory.

MoSi2 Composites for High Temperature Structural Applications

2011 ◽  
Vol 214 ◽  
pp. 103-107 ◽  
Author(s):  
Yagiz Uzunonat ◽  
Sinem Cevik Uzgur ◽  
S. Fehmi Diltemiz ◽  
Melih Cemal Kushan ◽  
Rabia Ölmez
Keyword(s):  
High Temperature ◽  
Structural Material ◽  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Structural Applications

In this paper, the basic limitations of superalloys’ in high temperature performances will be explained and then after giving the important properties of MoSi2, some interesting composites of this material will be discussed as a candidate structural material for gas turbine engines.

Long Term Thermal Stability of Several Gas Turbine Alloys

2005 ◽  
Author(s):  
L. M. Pike ◽  
S. K. Srivastava
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Gas Turbine ◽  
Operating Costs ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Haynes 230 ◽  
One Year ◽  
Thermal Stability Of

Ever increasing demands for lower gas turbine operating costs have led to the need for longer lasting components. This in turn, requires the availability of alloys which are reliable to such long lifetimes. In the mill produced condition, most alloys have desirable microstructures and mechanical properties. However, after exposure to the harsh temperatures found in gas turbine engines, the microstructures of most alloys will begin to change. The effects on the mechanical properties of such microstructural changes can range from mild deterioration to significant degradation. In this paper, the effects of thermal exposures at temperatures from 1200 to 1600°F for durations up to one year on the mechanical properties of three wrought gas turbine alloys will be reported. The alloys will include HAYNES® 188 alloy (Co-Ni-Cr-W), HAYNES 230® alloy (Ni-Cr-W), and HAYNES HR-120® alloy (Fe-Ni-Cr-Nb-N).

EFFECT OF CASTING DEFECT ON MECHANICAL PROPERTIES OF 17-4PH STAINLESS STEEL

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4463-4468
Author(s):  
JONG-YUP KIM ◽  
JOON-HYUN LEE ◽  
SEUNG-HOON NAHM
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Stainless Steel ◽  
Gas Turbine ◽  
Volume Fraction ◽  
Low Cycle Fatigue ◽  
Turbine Engines ◽  
Casting Defects ◽  
Gas Turbine Engines ◽  
Proportional Relationship

Damage and integrity evaluation techniques should be developed steadily in order to ensure the reliability and the economic efficiency of gas turbine engines. Casting defects may exist in most casting components of gas turbine engines, and the defects could give serious effect on mechanical properties and fracture toughness. Therefore, it is very important to understand the effect of casting defects on the above properties in order to predict the safety and life of components. In this study, specimens with internal casting defects, made from 17-4PH stainless steel, were prepared and evaluated and characterized based on the volume fraction of defects. The relation between mechanical properties such as tensile, low cycle fatigue and fracture toughness and volume fraction of defect has been investigated. As a result of the analysis, the mechanical properties of 17-4PH decreased as the defect volume fraction increased with very good linearity. The mechanical properties also showed an inversely proportional relationship to electrical resistivity.

Service Temperature Estimation of Turbine Blades Based on Microstructural Observations

1990 ◽  
Author(s):  
Jose M. Aurrecoechea ◽  
William D. Brentnall ◽  
Joseph R. Gast
Keyword(s):  
Mathematical Model ◽  
Turbine Blades ◽  
Turbine Engines ◽  
Computational Technique ◽  
Gas Turbine Engines ◽  
Service Temperature ◽  
Temperature Estimation ◽  
Gamma Prime ◽  
Diffusion Controlled ◽  
Nickel Base

Optical and electron metallographic (SEM) examination was performed on MAR-M-421 samples subjected to controlled furnace exposures, to quantify the microstructural changes associated with the prolonged high temperature exposures. Gamma prime size measurements were used to generate a mathematical model, based on diffusion controlled kinetics, designed to estimate temperatures. This computational technique was utilized to estimate exposure temperatures of turbine blades which had seen service in land based gas turbine engines. The engines had accumulated from 1,200 to more than 98,000 hours, operating under a variety of conditions. The procedure is generally applicable to commonly used gamma prime strengthened nickel-base superalloys.

Microstructure and Corrosion Properties of Mg-Zn-Ca-Zr Alloy for Biomedical Application

2013 ◽  
Vol 790 ◽  
pp. 11-15
Author(s):  
Dong Mei Jiang ◽  
Tang Sheng Yu ◽  
Dong Hua Jiang ◽  
Liang Guo ◽  
Zhan Yi Cao
Keyword(s):  
Solid Solution ◽  
Volume Fraction ◽  
Biomedical Application ◽  
Secondary Phase ◽  
Secondary Phases ◽  
Corrosion Properties ◽  
Lower Volume Fraction ◽  
Lower Volume ◽  
Fine Microstructure ◽  
Zr Alloy

The microstructuresandcorrosion properties of the as-cast Mg-Zn-Ca-Zralloys were investigated in this study. The results showed that the alloy was mainly composed of -Mg solid solution,Zr particle and the secondary phase of Ca2Mg6Zn3. The grain size of alloy specimens decreased with the increment of Zr content. The corrosion resistances were found to increase from 0.3% to 0.5% and then decrease from 0.5% to 0.7%. The Mg-4Zn-0.5Ca-0.5Zr had the best corrosion resistance in SBF solution.This was attributed to a combination of (1) the uniform and fine microstructure of alloy, (2) continuous distributions of the secondary phases, and (3) a lower volume fraction of Zr particles.

scholarly journals The ratio of hydrogelator to precursor controls the enzymatic hydrogelation of a branched peptide

Soft Matter ◽  
2020 ◽  
Vol 16 (44) ◽  
pp. 10101-10105
Author(s):  
Jiaqi Guo ◽  
Hongjian He ◽  
Beom Jin Kim ◽  
Jiaqing Wang ◽  
Meihui Yi ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Lower Volume Fraction ◽  
Lower Volume

Here, we report an apparently counterintuitive observation, in which a lower volume fraction of a branched peptide forms a stronger hydrogel after an enterokinase (ENTK) cleaves off the branch from the peptide.

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