Metallographic Investigation on the Effect of Cryogenic Temperature on Steel Weldments

2014 ◽  
Vol 629 ◽  
pp. 456-460 ◽  
Author(s):  
S. Rasool Mohideen ◽  
Ahmad Zaidi Ahmad Mujahid ◽  
Abdullah Shohaimi ◽  
S. Ravi
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Low Temperatures ◽  
Cryogenic Temperature ◽  
Liquid Nitrogen Temperature ◽  
Optical Microscope ◽  
Low Alloy Steel ◽  
Transmission Electron ◽  
Properties Of Materials

Materials are subjected to low temperatures either intentionally as in the case of cryogenic fuels or non-intentionally as in the case of aerospace environment and are observed to undergo changes in their properties. Microstructural changes are the premier indications of changes in the properties of materials. This paper investigates the effect of cryogenic temperature on the microstructure of low alloy steel weldments. The weldments were subjected to liquid nitrogen temperature of 77K and the microstructures were analyzed using optical microscope and transmission electron Microscope. A distinct change in the microstructure was observed which would reason out the changes in the mechanical properties of weldments.

Visualizing the Behavior of Dislocations—Seeing is Believing

MRS Bulletin ◽  
2008 ◽  
Vol 33 (2) ◽  
pp. 122-131 ◽  
Author(s):  
Ian M. Robertson ◽  
Paulo J. Ferreira ◽  
Gerhard Dehm ◽  
Robert Hull ◽  
Eric A. Stach
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Image Manipulation ◽  
Recording Media ◽  
Computational Power ◽  
Stage Design ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Rate Limiting

AbstractThe spatial resolution of the transmission electron microscope makes it an ideal environment in which to continuously track the real-time response of a system to an external stimulus and to discover and quantify the rate-limiting fundamental microscopic processes and mechanisms governing the macroscopic properties. Advances in instrumentation, stage design, recording media, computational power, and image manipulation software are providing new opportunities for not only observing the microscopic mechanisms but also measuring concurrently the macroscopic response. In this article, the capability of this technique as applied to mechanical properties of materials is highlighted.

Effect of Mg/Si Ratio on Hardening Behavior, Microstructure and Properties of Al-Mg-Si Alloys

2022 ◽  
Vol 905 ◽  
pp. 56-60
Author(s):  
Ya Ya Zheng ◽  
Tao Long ◽  
Bing Li
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Intergranular Corrosion ◽  
Corrosion Test ◽  
Electrochemical Test ◽  
Microstructure And Properties ◽  
Hardening Behavior ◽  
Transmission Electron ◽  
Precipitation Behaviour

The effects of Mg/Si ratio on precipitation behaviour and properties of Al-Mg-Si alloys were studied by using electrochemical test, corrosion test and transmission electron microscope (TEM). The results show that with the increases of Mg/Si ratio from 0.9 to 1.1, the density of the β" decreases, and the mechanical properties decrease. When the ratio of Mg/Si increases from 1.0 to 1.1, the density y of β" does not increase significantly, but the continuous degree of the MgSi phase decreases significantly. The source of cracks originate from MgSi phase, which reduces the mechanical properties. When the Mg/Si ratio is 0.9, the alloy is in an over-Si state, which results in serious intergranular corrosion (IGC).

scholarly journals Study on fracture behavior of individual InAs nanowires using an electron-beam-drilled notch

RSC Advances ◽  
2017 ◽  
Vol 7 (27) ◽  
pp. 16655-16661 ◽  
Author(s):  
Suji Choi ◽  
Jong Hoon Lee ◽  
Min Wook Pin ◽  
Dong Won Jang ◽  
Seong-Gu Hong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Fracture Behavior ◽  
Tensile Loading ◽  
Uniaxial Tensile ◽  
Transmission Electron ◽  
Inas Nanowires ◽  
Uniaxial Tensile Loading

The mechanical properties and fracture behavior of individual InAs nanowires (NWs) were investigated under uniaxial tensile loading in a transmission electron microscope.

Relation between internal boundaries and critical current in textured YBa2Cu3O7−δ: Transmission electron microscope observations

1998 ◽  
Vol 13 (10) ◽  
pp. 2800-2806 ◽  
Author(s):  
A. Khalfi ◽  
G. Trolliard ◽  
B. Soulestin ◽  
D. S. Smith ◽  
J. P. Bonnet ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Critical Current ◽  
Strong Coupling ◽  
Transmission Electron Microscope ◽  
Melting Zone ◽  
Optical Microscope ◽  
Microscope Examination ◽  
Transmission Electron ◽  
Superconducting Current ◽  
Misorientation Angles

The local critical current (Ic) at 77 K measured at the mm scale in a 60 mm long sample of YBa2Cu3O7−δ prepared by a melting zone process is correlated to the microstructure. Lower values of Ic (<20 A) were obtained in a part of the sample which optical microscope examination showed to be generally polycrystalline. In contrast, the rest of the sample, consisting mostly of large textured domains, gave values for Ic of 120 A and above. Transmission electron microscope observations revealed that the textured domains contain internal boundaries. Depending on the scale of observation, the misorientation angles across the boundaries could vary from a few tenths of a degree up to a few degrees. This seems characteristic for boundaries in textured material which allow strong coupling of the superconducting current across themselves.

The Processing, Microstructure and Mechanical Properties of Low Alloy Wear Resistance Steels

2011 ◽  
Vol 399-401 ◽  
pp. 259-263 ◽  
Author(s):  
Xue Min Wang ◽  
Pei Zhu Li
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Electron Microscope ◽  
Retained Austenite ◽  
Lath Martensite ◽  
Optical Microscope ◽  
Direct Quenching ◽  
Microstructure And Mechanical Properties ◽  
Transmission Electron ◽  
Multi Phase

With the aid of optical microscope, transmission electron microscope, scanning electron microscope, the processing and chemical composition on the microstructure and mechanical properties of low alloy wear resistance steels have been investigated. The results show that by multi-alloying design and TMCP processing the low alloy wear resistance steels has good synthetic properties. The lath martensite, multi phase microstructure composed of bainite and retained austenite film could be obtained after direct quenching. The lath martensite with retained austenite shows better wear resistance than bainite. Under the two bodies abrasive wear condition the characteristics of worn surface reveals that the main wear mechanism is micro-cutting.

Influence of Microstructure and Precipitates on the Strength of Container Steel

2012 ◽  
Vol 586 ◽  
pp. 225-229
Author(s):  
Jia Yan Ma ◽  
Wen Liang ◽  
Rong Dong Han ◽  
Yun Guan ◽  
Zhao Jun Deng
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Transmission Electron Microscope ◽  
Optical Microscope ◽  
The Other ◽  
Precipitation Strengthening ◽  
Strengthening Effect ◽  
Transmission Electron ◽  
Uniform Dispersion ◽  
Scanning Electron

The variation rules of strength with the microstructure and precipitates of container steel were studied by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the microstructures of four kinds of test steels are all bainite and M/A island, but the number and size of islands of M/A and precipitates exist obvious difference: two kinds of test steels have fewer precipitates and more M/A islands, however, the other two kinds of steels are on the contrary. As for the former two kinds steels, the number of M/A islands is larger, and the size is smaller, the strength of steel is higher; For the later two kinds steels, the number of precipitates less than 30nm is larger, and distribution is more uniform dispersion, the strength is higher, precipitation strengthening effect is better. Getting lots of small and uniform M/A islands or precipitates is an effective way of improving the performance of steel.

Effect of Heat Treatment on the Microstructure of Cu-Cr-Zr Alloy

2017 ◽  
Vol 727 ◽  
pp. 166-170 ◽  
Author(s):  
Li Jun Peng ◽  
Hao Feng Xie ◽  
Gao Lei Xu ◽  
Guo Jie Huang ◽  
Zhen Yang
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Volume Fraction ◽  
Homogenization Temperature ◽  
Eutectic Structure ◽  
Optical Microscope ◽  
Heat Treatments ◽  
Transmission Electron ◽  
The Matrix ◽  
Zr Alloy

Effect of Heat treatments on microstructure in a Cu-0.71Cr-0.12Zr alloy (in wt.%) have been investigated. The microstructures are analyzed by optical microscope, scanning electron microscope, transmission electron microscope and high-resolution transmission electron microscope after each step of heat treatments. The results show that the as-cast microstructure of Cu-Cr-Zr alloy is Cu matrix, Cr dendrite and eutectic structure which is composed of Cu and Cu5Zr phase with a fine lamellar structure. By increasing the homogenization temperature or prolonging the holding time, the eutectic structure is dissolved into the matrix gradually and the volume fraction of the Cr phases is obviously reduced. The precipitation of Cr phase prevents from Zr-rich phases dissolving in the matrix. And the proper homogenizing process is 900°C×12 h. When the alloy aged at 450°C for 24 h, the crystallography of Cr precipitates and the orientation relationship between Cr precipitates and Cu matrix is bcc structure and KS-OR, respectively. The disk-shaped precipitate is identified as Cu5Zr phase and their habit plane is parallel to {111}Cu plane.

In Situ Straining Experiments On Fe70AL30 Single Crystals

1994 ◽  
Vol 364 ◽  
Author(s):  
G. Molenat ◽  
H. Rösner ◽  
E. Nembach
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Single Crystals ◽  
Yield Stress ◽  
Transmission Electron Microscope ◽  
Intermetallic Alloys ◽  
Temperature Range ◽  
Transmission Electron

AbstractWith an aim to contributing to the understanding of the mechanical properties of Fe3Al-based intermetallic alloys, Fe-30 at. % Al single crystals have been strained in a transmission electron microscope below and in the temperature range of the yield stress anomaly (at 300K and 573K respectively).

Effects of Biaxial Pre-Stretching on Microstructures and Mechanical Properties of 2024 Aluminum Alloy Thin Plates

2014 ◽  
Vol 472 ◽  
pp. 607-611 ◽  
Author(s):  
Jian Jun Wu ◽  
Rui Chao Guo ◽  
Hao Li ◽  
Shen Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Electron Microscope ◽  
Plane Strain ◽  
Transmission Electron Microscope ◽  
Strain State ◽  
Thin Plates ◽  
2024 Aluminum Alloy ◽  
Transmission Electron

Biaxial pre-stretching is implemented by bulge forming model. After engraved circular grids on new quenching blank, the specimen is biaxially pre-stretching formed. We use JGX-2 Engineering Microscope to measure principal pre-stretching points with 1.5%-3.1% elongation, which are in plane strain state. Hardness is measured by GYZJ 934-1 type Barcol Hardness and microstructures are observed by JEM-200CX Transmission Electron Microscope. The result shows that the influence on tensile strength of biaxial pre-stretching for new quenching state specimen is not big; however, it is the principal pre-stretching quantity 1.75% that improves microstructure and hardness.

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