Effect of Nitrogen on the Mechanical Properties of Heat-Resisting Steel

2012 ◽  
Vol 535-537 ◽  
pp. 571-575
Author(s):  
Xiao Liu ◽  
Long Mei Wang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Room Temperature ◽  
Rupture Strength ◽  
N Addition ◽  
Creep Rupture Strength ◽  
Test Steel ◽  
Scanning Electron

In this paper, the effect of N addition on mechanical properties of 21Cr-11Ni austenitic heat-resisting stainless steel was investigated. Scanning electron microscopy was used to study the fracture surfaces in the steels. N in 21Cr–11Ni heat-resisting steel can play a role of stabling austenite and ensuring the structure and mechanical properties in high temperatures. Fracture is changed from cleavage to ductile fracture to 21Cr–11Ni heat-resisting steel, and the strength of test steel are improved at room temperature by adding N, the tensile strength is increased by 8.33%. And the creep rupture strength is improved. The fracture time of the steel containing 0.2% N is 3.2 times higher than the steel containing 0.14% N at 1144K.

Mechanical Behavior and Failure Mechanisms of SCS-6/Ti3Al Composites

1990 ◽  
Vol 194 ◽  
Author(s):  
S. M. Jeng ◽  
C. J. Yang ◽  
J.-M. Yang ◽  
D. G. Rosenthal ◽  
J. Goebel
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Room Temperature ◽  
Failure Mechanisms ◽  
Crack Initiation And Propagation ◽  
Al Composite ◽  
Initiation And Propagation ◽  
Bend Tests ◽  
Scanning Electron

AbstractThe mechanical properties and failure mechanisms of the SCS-6/Ti3Al composite have been studied. Both tensile and notched bend tests were conducted at room temperature on the monolithic and fiber-reinforced Ti-25Al-10Nb-3V-1Mo. Optical and scanning electron microscopy were used to study the crack initiation and propagation mechanisms. The role of the fiber, matrix and interfacial properties on the composite behavior was also assessed.

Effect of Pressure of Nitrogen Atmosphere on Microstructure and Mechanical Properties of Ti(C, N)–12WC–16Ni–4Mo2C Cermet

2012 ◽  
Vol 602-604 ◽  
pp. 540-543
Author(s):  
Teng Biao Zheng ◽  
Ping Feng ◽  
Hai Yan Lei
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Rupture Strength ◽  
Nitrogen Pressure ◽  
Nitrogen Atmosphere ◽  
Vacuum Sintering ◽  
Sintering Atmosphere ◽  
Grain Sizes ◽  
Scanning Electron

The effect of sintering atmosphere and nitrogen pressure on microstructure of Ti(C, N)–12WC–16Ni–4Mo2C cermet were investigated by scanning electron microscopy (SEM) and optical microscopy (OM), the transverse rupture strength (TRS), porosities, volume fractions of phases and grain sizes were determined. Results show that nitrogen pressure has a significant impact on TRS, appropriate nitrogen pressure could improve TRS. Vacuum sintering promotes the densification of sintered body, however, nitrogen atmosphere sintering could gain maximal TRS. Nitrogen atmosphere sintering facilitates the formation of inner rim phase and reduces the dissolution of TiC and TiN, small grain size is gained.

Modification of DABA/BMI Composites by Silane Compound and Fumed SiO2

2012 ◽  
Vol 622-623 ◽  
pp. 1006-1013
Author(s):  
Nazakat Alia ◽  
Qiu Yu Zhang ◽  
Yin Wu ◽  
Ying Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Thermal Properties ◽  
Fumed Silica ◽  
Heat Stability ◽  
Nano Composite ◽  
Bending Modulus ◽  
Scanning Electron

In this present investigation, at first, Dially bisphenol A (DABA)/Bismaleimide (BMI) system was modified with gamma-aminopropyltriethoxy silane (KH550). The objective of the work was to study the effect of addition of various weight percentages of KH550 into BMI/DABA composites on its mechanical properties, thermal properties and morphorogy. Further modification was carried out with fumed silica. The role of KH550 was discussed in these composites prepared. Nancomposites were characterized by differential DSC, TGA, and scanning electron microscopy SEM. TGA results confirmed that the heat stability of the nano composite DABA/BMI/KH550 is improved compared with DABA/BMI system. SEM results indicated that the fumed silica dispersed homogeneously in DABA/BMI/KH550 matrix on nanoscale. Mechanical results shows that newly developed system has improved bending modulus to 4.0GPa, while with incorporation of fumed SiO2 impacted strength also improved to 20.60kJ/m2.

Effects of Ca and Y on Microstructures and Mechanical Properties of Magnesium Alloy AZ81

2014 ◽  
Vol 488-489 ◽  
pp. 154-157
Author(s):  
Lei Lei Chen ◽  
Quan An Li ◽  
Jiang Chang Xie
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Room Temperature ◽  
Microstructure And Mechanical Properties ◽  
Mechanical Properties Testing ◽  
Microstructures And Mechanical Properties ◽  
Scanning Electron

By the scanning electron microscopy, the microstructure and mechanical properties testing, the effect of Ca and Y on the microstructure and mechanical properties of magnesium alloy AZ81 are investigated in this paper. The results show that with Ca and Y addition, the grain size is refined. And with the β-Mg17Al12 phase reducing significantly, there will be the precipitation of Al2Ca and Al2Y. Meanwhile, the mechanical properties of AZ81 magnesium alloy are enhanced at room temperature and 150°C.

The Influence of B4C on Mechanical Properties of MgO-SiC Based Refractory Castables

2013 ◽  
Vol 634-638 ◽  
pp. 2397-2401 ◽  
Author(s):  
Jun Cong Wei ◽  
Jing Wang ◽  
Jun Bo Tu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Liquid Phase ◽  
Room Temperature ◽  
The Other ◽  
Cold Strength ◽  
Refractory Castables ◽  
Direct Binding ◽  
Scanning Electron

The effects of B4C addition on the room temperature physical properties and hot mechanical properties of MgO-SiC based refractory castables were investigated using magnesia and SiC fines as starting materials and silica fume as a binder. The microstructure was characterized by scanning electron microscopy (SEM). The results showed that drying strength of MgO-SiC based castables decreased with the increase in B4C addition, the immediate temperature strength and hot temperature strength increased. The HMOR at 1400°C for 0.5h decreased. This is because B4C oxidized and produced a liquid phase during heating, contributing to sintering and making the material denser. So the cold strength increased. On the other hand, due to the formation of liquids, direct binding reduced and the HMOR decreased

Microstructure and Mechanical Properties of as-Forged Ti-47Al-2Cr-2Nb-Y Alloy

2011 ◽  
Vol 311-313 ◽  
pp. 1873-1878
Author(s):  
Shu Zhi Zhang ◽  
Fan Tao Kong ◽  
Yu Yong Chen ◽  
Shu Long Xiao ◽  
Chao Cao
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Room Temperature ◽  
B2 Phase ◽  
Hot Pack ◽  
Scanning Electron

Ti-47Al-2Cr-2Nb-Y alloy pancake were produced by hot-pack forging. The microstructure of as-forged Ti-47Al-2Cr-2Nb-Y alloy were investigated by optical microscopy and scanning electron microscopy, showing that the forged alloy was composed of fine γ grains and retain cast lamella colonies surrounded by elongated B2 phase. Tensile properties of the material showed that yield strength (YS) and ultimate tensile strength (UTS) were decreased from 500MPa and 612MPa at room temperature to 420 MPa and 462 MPa at 800°C, respectively. With the temperature increasing to 900°C, elongation reached 120%.

Study on Epoxy Based Magnetorheological Elastomers

2011 ◽  
Vol 306-307 ◽  
pp. 852-856 ◽  
Author(s):  
Xiang Wang ◽  
He Yi Ge ◽  
Hua Shi Liu
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Iron Content ◽  
Room Temperature ◽  
Magnetorheological Elastomers ◽  
The Matrix ◽  
Mr Effect ◽  
Scanning Electron

To improve the mechanical properties and the MR effect of MRE, we use flexible epoxy as the matrix of MRE. It shows that both the mechanical properties and the MR effect of epoxy based MRE improved. At room temperature the highest absolute modulus increase was 203 MPa when the intensity of magnetic field was 0.2T while the carbonyl iron content was 71.4%. Temperature influenced the MR effect. When at -40°C the maximum storage modulus increased more than 2356 MPa and changed with the temperature. Meanwhile, the morphology of the epoxy based MRE was studied by scanning electron microscopy (SEM).

The Effect of Gallium on the Mechanical Properties of Superalloy K444

2012 ◽  
Vol 452-453 ◽  
pp. 31-34
Author(s):  
Xuan Xiao ◽  
Zeng Chao ◽  
Xu Le ◽  
Li Yuan Sheng ◽  
Yong An Guo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Room Temperature ◽  
Standard Heat Treatment ◽  
Standard Heat ◽  
Gallium Content ◽  
Scanning Electron

In order to figure out whether Gallium works in the superalloy K444, its composition had been modified by adding about 0.003 wt.% and 0.01 wt.% Ga, respectively. Mechanical properties of the modified superalloy K444 were investigated by using scanning electron microscopy (SEM) after standard heat treatment. Gallium had no significant effect on the tensile strength at room temperature and 900 °C. Gallium had a little effect on the tensile plasticity at room temperature and 900 °C. The plasticity is better in the modified K444 alloy containing 0.003wt. % Ga, however, the plasticity became worse in the alloy containing 0.01wt. % Ga. As for plasticity, the optimum Gallium content should be 0.003 wt. % for the superalloy K444.

FABRICATION OF CARBON NANOSTRUCTURES BY LASER ASSISTED CHEMICAL REACTION

NANO ◽  
2006 ◽  
Vol 01 (01) ◽  
pp. 73-76 ◽  
Author(s):  
JONGBOK PARK ◽  
SUNGHO JEONG ◽  
OK HWAN CHA ◽  
MUN SEOK JEONG ◽  
DO-KYEONG KO ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Atmospheric Pressure ◽  
Carbon Nanostructures ◽  
Room Temperature ◽  
Simple Method ◽  
Pulsed Nd:Yag Laser ◽  
Transmission Electron ◽  
Scanning Electron

In this work, a simple method is reported for the synthesis of bundles of carbon nanostructures under room temperature and atmospheric pressure. A pulsed Nd:YAG laser (355 nm, 10 Hz) is focused into the mixture of ferrocene and xylene solutions to produce the nanostructures in which ferrocene plays the role of a catalyst while xylene is the carbon source for nanostructure growth. During the period of irradiation, the color of solution turns into dark brown from transparent orange. Upon the completion of irradiation, typically for an hour, a variety of bundles of carbon nanostructures are found in the solution. Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) are used to investigate the nanostructures.

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

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