scholarly journals Low-Temperature Strengths and Ductility of Various Tungsten Sheets

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Yutaka Hiraoka ◽  
Hiroaki Kurishita
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Electron Microscope ◽  
Low Temperature ◽  
Fracture Surface ◽  
Optical Microscope ◽  
Transgranular Fracture ◽  
Bend Tests ◽  
Point Bend ◽  
Scanning Electron

We used three kinds of tungsten sheets in this study. First, we examined microstructure such as grain size distribution using an optical microscope. Secondly, we carried out three-point bend tests at temperatures between about 290 and 500 K. Then, we examined fracture surface of a failed specimen using a scanning electron microscope. Lastly, by analyzing all these results, we evaluated apparent intergranular and transgranular fracture strengths and discussed strengths and ductility of tungsten. Additionally, we compared mechanical properties of tungsten with those of molybdenum.

The Effect of Cryogenic Treatment on the Microstructure and Properties of Ti-6Al-4V Titanium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 899-903 ◽  
Author(s):  
Kai Xuan Gu ◽  
Zhi Qiang Li ◽  
Jun Jie Wang ◽  
Yuan Zhou ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Electron Microscope ◽  
Low Temperature ◽  
Fracture Surface ◽  
Cross Section ◽  
Cryogenic Treatment ◽  
Great Influence ◽  
Microstructure And Properties ◽  
Scanning Electron

The effect of cryogenic treatment on the microstructure and properties of Ti-6Al-4V has been studied in this paper. The program controlled SLX cryogenic box was used to conduct the cryogenic treatment and the subsequent low temperature temper. The scanning electron microscope was used to study the morphology of microstructure and fracture surface. As the results show that the cryogenic treatment increases the elongation of Ti-6Al-4V from 16.5 percent to 24.5 percent, at the same time, the strength increases slightly, this indicates that cryogenic treatment can improve the comprehensive mechanical properties. The microstructure measurement revealed that there is a tendency of reduction in the precipitated particles after cryogenic treatment. The cross section is flat and the size of dimples is more uniform. It is concluded that the change in the precipitation particle had a great influence in the mechanical properties.

Relationship between Tensile Deformation and Crystallographic Orientation of Grains in Al-Mg-Si Alloys with Cu

2007 ◽  
Vol 26-28 ◽  
pp. 129-132 ◽  
Author(s):  
Junji Tsukiyama ◽  
Kenji Matsuda ◽  
Yasuhiro Uetani ◽  
Susumu Ikeno
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Electron Microscope ◽  
Fracture Surface ◽  
Crystallographic Orientation ◽  
Tensile Deformation ◽  
Hardness Measurement ◽  
Tensile Behavior ◽  
Schmid Factor ◽  
Scanning Electron

It is very popular to improve mechanical properties of Al-Mg-Si alloys by adding other element. For example, it is well known that addition of transition metals is useful because the refinement of grain size can be achieved, and with the addition of Cu to Al-Mg-Si alloy can increase the strength and hardness of the materials. Also, there are a few reports about the addition of Ag, which is particularly good for elongation. However, even now it has not been clarified yet why Cu and Ag are useful in improving alloys elongation. In this work, we have investigated the tensile behavior of excess Si-type Al-Mg-Si alloys, which contain Cu. The tensile test and hardness measurement were carried out. Scanning electron microscope (SEM) was used to investigate the fracture surfaces and individual crystallographic orientation. After small additional deformation, the crack was observed by the interface between higher Schmid Factor (S.F.) and lower S.F. grains. It was thought that this crack influenced fracture from fracture surface.

scholarly journals Enhancing the Mechanical Properties of Hot Roll Bonded Al/Ti Laminated Metal Composites (LMCs) by Pre-Rolling Diffusion Process

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 795 ◽  
Author(s):  
Cheng Zhang ◽  
Shouxin Wang ◽  
Hanxue Qiao ◽  
Zejun Chen ◽  
Taiqian Mo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Diffusion Process ◽  
Energy Dispersive Spectrometer ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Interfacial Structure ◽  
Metal Composites ◽  
Diffusion Temperature ◽  
Scanning Electron

In this study, the traditional hot rolling to fabricate Al/Ti laminated metal composites (LMCs) was improved by using a pre-rolling diffusion process. The effect of the pre-rolling diffusion on microstructure and mechanical properties of Al/Ti LMCs were investigated by various methods, such as optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and tensile tests. The results show that, with increasing diffusion temperature, the thickness in diffusion layer was increased and the mechanical properties of LMCs were improved obviously, which was attributed to the optimized interfacial structure after diffusion process. In addition, the formation of TiAl3 intermetallic compounds (IMCs) was detected in the bonding interface, which played an important role in improving the mechanical properties for Al/Ti LMCs. The predicted results of stress-strain curves from rule of mixture (ROM) indicated that, there existed an extra interfacial strengthening in Al/Ti LMCs beside the mechanical properties provided by the contribution of constituent layers. The pre-rolling diffusion process is effective for the optimization of interfacial structure and improvement of mechanical properties in Al/Ti LMCs.

scholarly journals Solidification, Microstructure and Mechanical Properties of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr Cast Alloy with Erbium Addition

2018 ◽  
Vol 202 ◽  
pp. 01001
Author(s):  
R. Ahmad ◽  
A.M.M. Elaswad ◽  
M. Z. Hamzah ◽  
N. R. Shahizan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Microstructure Analysis ◽  
Cooling Curve ◽  
Scanning Electron

The thermal parameters of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr cast alloy with 0.25 wt.% of erbium (Er) were evaluated by the computer-aided cooling curve thermal analysis(CA CCTA), whereas the microstructure analysis was investigated by the optical microscope and scanning electron microscopy. Results from the cooling curve and microstructure analysis showed that Er altered the grain size of the alloys. In addition, the grain size was reduced by approximately 19.6% with the addition of Er. Scanning electron microscopy results showed that Er formed an Mg-Zn-Nd-Er phase which distributed along the grain boundaries. Furthermore, the mechanical properties were investigated by hardness and tensile tests with Er addition. The addition of 0.25 wt.% of Er significantly improved the ultimate tensile strength and yield strength. In addition, the hardness value of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr increased by 13.9% with Er addition.

Mechanical Properties and Microstructures of A356 Alloy Prepared by Casting Combined With Forging

2017 ◽  
Author(s):  
Zhenglong Liang ◽  
Qi Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
A356 Alloy ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Forging Process ◽  
Scanning Electron

A novel process which combines casting with forging during one process was proposed to improve mechanical properties and refine microstructure. The microstructure evolution of as-cast samples and forged samples were analyzed by optical microscope and scanning electron microscope (SEM). The tensile properties and micro-hardness were also measured. The results show that combination of casting and forging can improve microstructure and decrease porosity of casting samples, consequently contributing to a better fatigue performance. The ultimate tensile strength and elongation were increased after forging process, however, the yield strength and micro-hardness decreased.

Effects of Microporosity on the Tensile Properties of Aluminum Alloy

2011 ◽  
Vol 422 ◽  
pp. 627-631 ◽  
Author(s):  
Xie Hua Li ◽  
Li Zi He ◽  
Yi Heng Cao ◽  
Pei Zhu ◽  
Ya Ping Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hydrogen Content ◽  
Optical Microscope ◽  
Slip Step ◽  
Inclusion Content ◽  
1050 Aluminum Alloy ◽  
Scanning Electron

The influences of cooling rate, hydrogen inflating time, degassing time, inclusion content on the distribution of pores within the ingot , hydrogen content and the mechanical properties of 1050 aluminum alloy were investigated by tensile test, optical microscope(OM), scanning electron microscope(SEM). With the increasing inflating hydrogen time, the hydrogen content increases, while, the strengths and elongation decrease. With the increasing degassing time, the hydrogen content decreases, while, the strengths and the elongation increase. With increasing cast temperature, the hydrogen content remains constant at first and increases obviously from 7200C to 7600C, while the strengths and the elongation decrease gradually. The crack is mainly originated at outcrop of slip step, inclusion and porosity.

The Elaboration of an Iron Aluminium Alloy and the Study of Impact of the Addition Element on its Physical and Mechanical Properties

2013 ◽  
Vol 686 ◽  
pp. 211-215
Author(s):  
Nadia Metidji ◽  
Nacer Eddine Bacha ◽  
Djamal Saidi ◽  
Slimane Boutarfaia
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Morphological Changes ◽  
Physical And Mechanical Properties ◽  
Antiphase Domain ◽  
Optical Microscope ◽  
Micro Hardness ◽  
X Ray ◽  
B Additions ◽  
Scanning Electron

This work has been undertaken in order to determine the effect of alloying with Ni, Mo and B additions on physical and mechanical properties of FeAl alloys. The structural evolutions and morphological changes alloys were characterized by X. ray diffractometry (XRD), Scanning Electron Microscope (SEM) and an Optical Microscope. Antiphase domain sizes and morphologies are reported and correlations between such ordening phenomena, phase precipitations and mechanical properties (micro hardness at low temperature) are discussed.

Effect of Different Tempering Temperatures on Microstructure and Impact Property of 20CrMnTi Steel

2014 ◽  
Vol 900 ◽  
pp. 92-95
Author(s):  
Sheng Xu Liu ◽  
Yi Qiang Xiao ◽  
Ming Long Kang ◽  
Jian Min Zeng ◽  
Guo An Wang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Low Temperature ◽  
Fracture Morphology ◽  
Optical Microscope ◽  
Impact Property ◽  
Medium Temperature ◽  
The Impact ◽  
Type Of Fracture ◽  
Scanning Electron

The effect of different tempering temperatures on microstructure and impact property of 20CrMnTi steel has been studied on Zwick/roell Amsler PKP 450 pendulum machine, SU-8020 scanning electron microscope (SEM) and optical microscope. The results shows that the impact property of 20CrMnTi steel is dramatically improved after high-temperature tempering. However, the minimum value occurs when it was tempered at 350°C because of low-temperature tempering brittlement at this degree. The SEM fracture morphology was typical dimples after high temperature tempering, and the type of fracture was ductile fracture; the type of cleavage characteristic and quasi cleavage characteristic were generated on the fracture morphology at low-temperature and medium-temperature tempering respectively, and the type of fracture was brittle.

Effect of Interface Improving on Morphology and Properties of Coir Fiber/LLDPE Bio-Composites

2011 ◽  
Vol 217-218 ◽  
pp. 1245-1248 ◽  
Author(s):  
Hong Sheng Tan ◽  
Yuan Zhang Yu ◽  
Jing Zhang
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Fracture Surface ◽  
Impact Strength ◽  
Interfacial Adhesion ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Coir Fiber ◽  
Interface Morphology ◽  
Scanning Electron

The mechanical properties of coir fiber/line low density polyethylene (LLDPE) bio-composites were studied and micrographs of fracture surface of impact specimens for the composites were analyzed by scanning electron microscope (SEM). The flexural and impact strength of the composite with a compatilizer were higher than that of the composite without a compatilizer. The results of interface morphology of the composites with a compatilizer show better interfacial adhesion than that of the composites without one by SEM. That compatibility between the fiber and LLDPE resin is improved on, which is essential reason of rigidity and toughness increase of the composites.

The Oxide Inclusion and Heat-Affected-Zone Toughness for Low Carbon Bridge Steels

2012 ◽  
Vol 562-564 ◽  
pp. 31-34
Author(s):  
Shu Rui Li ◽  
Xue Min Wang ◽  
Chao Chao Zheng ◽  
Xin Lai He
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Scanning Electron Microscope ◽  
Impact Energy ◽  
Heat Input ◽  
Oxide Inclusion ◽  
Optical Microscope ◽  
Low Carbon ◽  
Temperature Impact ◽  
Scanning Electron

By welding thermo-simulation and actual welding practices, the microstructure and properties of low carbon bridge steels has been studied with the aid of optical microscope, scanning electron microscope. The experimental results show that by the oxide introducing melting technology there are many complex inclusions composed of oxide containing Ti and MnS. These inclusions are spherical and they are distributed homogeneously. During the welding thermo-simulation these oxide inclusions will promote the nucleation of acicular ferrite and make the microstructure in HAZ finer. Therefore the toughness in HAZ is good whether in welding thermo-simulation even if the heat input reaches to 200kJ/cm. In actual welding the heat input is 88kJ/cm and the low temperature impact energy still can reach 110J.

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