Primary α phase and its effect on the impact ductility of a high Cr content cast Ni-base superalloy

2012 ◽  
Vol 527 ◽  
pp. 176-183 ◽  
Author(s):  
Liang Zheng ◽  
Chengbo Xiao ◽  
Guoqing Zhang ◽  
Bo Han ◽  
Dingzhong Tang
Keyword(s):  
Cr Content ◽  
Α Phase ◽  
The Impact ◽  
Impact Ductility ◽  
Base Superalloy

scholarly journals Analysis of the Influence of Production Method, Crumb Rubber Content and Stabilizer on the Performance of Asphalt Rubber

2020 ◽  
Vol 10 (16) ◽  
pp. 5447
Author(s):  
Haibin Li ◽  
Wenbo Li ◽  
Ahmed Abdulakeem Temitope ◽  
Dong Zhao ◽  
Guijuan Zhao ◽  
...  
Keyword(s):  
High Temperature ◽  
Positive Impact ◽  
Control Variable ◽  
Production Method ◽  
Crumb Rubber ◽  
Temperature Behavior ◽  
Moderate Amount ◽  
Cr Content ◽  
Asphalt Rubber ◽  
The Impact

Asphalt rubber (AR) is often described as an environmentally friendly material due to the incorporation of recycled rubber from used tires and its improved service life. Its field application is influenced by many factors. In order to evaluate the impact of different factors such as crumb rubber (CR) content, stabilizer and the production method on the performance of rubber powder modified asphalt, two different matrix asphalts were prepared, the basic experiments, control variable methods and several related tests were thereafter conducted. The results showed that a moderate amount of CR could enhance the pavement performance. The suitable CR content was 20–25% for 90# matrix asphalt and 22–26% for 70# matrix asphalt. The stabilizer had a positive impact on the AR’s high temperature behavior and was beneficial to the storage of AR, but it did not make a significant influence on low temperature behavior. In addition, different methods brought certain performance differences. Though AR produced with the heat fusion method had better high-temperature performance, the rubber particles would easily disperse and melt in the asphalt during the shearing process, which gave AR more balanced physical performance. This study identifies the shearing method as the optimal choice for site construction and provides a wider application range for asphalt rubber in the road construction field. The selection of parameters depends on the construction areas and performance requirements.

Hierarchical structure of the triclinic α-phase crystal in nylon 6,12 mediated by two-dimensional confinement

2020 ◽  
Vol 53 (1) ◽  
pp. 27-33
Author(s):  
Ziwei Lai ◽  
Shuailin Zhang ◽  
Nan Zheng ◽  
Shichen Yu ◽  
Masaki Ageishi ◽  
...  
Keyword(s):  
Hierarchical Structure ◽  
Phase Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hierarchical Nanostructure ◽  
Α Phase ◽  
Triclinic Symmetry ◽  
Phase Crystal ◽  
Unit Cells ◽  
The Impact

It has been recognized that macromolecular chains can self-assemble into a hierarchical structure from lamellae to spherulites in bulk crystallization. However, little account has been taken of crystal symmetry effects on the hierarchical nanostructure in polymers under cylindrical confinement. In this research, a model polymer, nylon 6,12, most commonly occurring in the triclinic α phase, was chosen in order to demonstrate the effect of triclinic symmetry on the 2D-constrained polymer nanostructure. The self-arranging unit of nylon 6,12 takes various forms, including stems, unit cells, hydrogen-bonded sheets, lamellae and complex spherulites, which is an essential structural feature for investigating hierarchical nanostructure. The rod nanostructure in confinement was examined by cross-checking electron and X-ray diffraction techniques. It is found that the a* axis of the α-phase cell is inclined at about ±6–11° to the rod long axis within the a*b* plane around the c axis (c axis ⊥ rod long axis). The rotation of the a*b* plane most likely results from the impact of the triclinic symmetry on the molecular chain packing under 2D confinement. A mechanism for this a*b* plane tilting is proposed.

scholarly journals Impact of Nano-Scale Distribution of Atoms on Electronic and Magnetic Properties of Phases in Fe-Al Nanocomposites: An Ab Initio Study

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1059 ◽  
Author(s):  
Ivana Miháliková ◽  
Martin Friák ◽  
Yvonna Jirásková ◽  
David Holec ◽  
Nikola Koutná ◽  
...  
Keyword(s):  
Ab Initio ◽  
Density Functional ◽  
Nearest Neighbor ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Α Phase ◽  
Ordered Intermetallic ◽  
Random Structures ◽  
The Impact

Quantum-mechanical calculations are applied to examine magnetic and electronic properties of phases appearing in binary Fe-Al-based nanocomposites. The calculations are carried out using the Vienna Ab-initio Simulation Package which implements density functional theory and generalized gradient approximation. The focus is on a disordered solid solution with 18.75 at. % Al in body-centered-cubic ferromagnetic iron, so-called α -phase, and an ordered intermetallic compound Fe 3 Al with the D0 3 structure. In order to reveal the impact of the actual atomic distribution in the disordered Fe-Al α -phase three different special quasi-random structures with or without the 1st and/or 2nd nearest-neighbor Al-Al pairs are used. According to our calculations, energy decreases when eliminating the 1st and 2nd nearest neighbor Al-Al pairs. On the other hand, the local magnetic moments of the Fe atoms decrease with Al concentration in the 1st coordination sphere and increase if the concentration of Al atoms increases in the 2nd one. Furthermore, when simulating Fe-Al/Fe 3 Al nanocomposites (superlattices), changes of local magnetic moments of the Fe atoms up to 0.5 μ B are predicted. These changes very sensitively depend on both the distribution of atoms and the crystallographic orientation of the interfaces.

Thermal Ageing Embrittlement of Casting Duplex Stainless Steels for Nuclear Power Plant

2010 ◽  
Author(s):  
Yuhong Yao ◽  
Jianfeng Wei ◽  
Jiangnan Liu ◽  
Zhengpin Wang ◽  
Yu Wang
Keyword(s):  
Stainless Steels ◽  
Thermal Aging ◽  
Nuclear Power ◽  
Power Plants ◽  
Ageing Time ◽  
Thermal Ageing ◽  
Duplex Stainless Steels ◽  
Impact Properties ◽  
Α Phase ◽  
The Impact

Cast duplex stainless steels (CSS) used for PWR pipes are degraded due to thermal ageing embrittlement during long-term service at 288 °C to 327 °C. Z3CN20-09M Cast duplex Stainless Steels (CSS) made in France for domestic nuclear power plants were thermally aged at 400 °C for 100 h, 300 h, 1000 h, 3000 h and 10000 h. The tensile properties and the impact properties at different thermal aging duration were measured and the effects of the thermal aging time on the microscopic structures and substructures of Z3CN20-09M were respectively investigated by optical microscopy and transmission electron microscopy. The results showed that the tensile strengths of Z3CN20-09M CSS increased gradually with the increment of the thermal ageing time, whereas the impact properties decreased with the prolonging of the thermal ageing time. After long thermal ageing time the dislocation configurations were greatly changed in austenite, and there were precipitates along the austenite-ferrite interface. Moreover, the iron-rich α phase and the chromium-rich α phase precipitated in ferrite aged for 10000h by nucleation and growth rather than the spinodal decomposition. All of above revealed that Z3CN20-09M CSS became brittle during thermal ageing.

Effect of Cr Content on Impact and Abrasion Properties and Mechanisms of Low Carbon Alloy Steel at Corrosive Condition

2010 ◽  
Vol 152-153 ◽  
pp. 1395-1398
Author(s):  
Guo Dong Sun ◽  
Chang Hua Liu
Keyword(s):  
Plastic Deformation ◽  
Alloy Steel ◽  
Impact Energy ◽  
Chromium Content ◽  
Surface Material ◽  
Low Carbon ◽  
Fatigue Wear ◽  
Cr Content ◽  
The Impact ◽  
Accumulated Deformation

Impact and abrasion properties of the low carbon alloy steel with different chromium content in acid-ironstone slurry were investigated. The test was carried out by a MLD-10 tester with impact energy of 1.2 J. By analysing the morphology of worn surfaces and the metallographs of the subsurface of the specimen, the impact corrosion and abrasion mechanism was investigated. The results show that the percentage of wear mass loss decreases along with the increment of the Cr content. At the impact energy of 1.2 J, the impact corrosion and abrasion mechanism of low carbon alloy steel with 3% Cr content is the deforming fatigue wear,the mechanism of low carbon alloy steel with 6% Cr content is that shallow spallation due to accumulated deformation for a shorter time and removal of surface material due to multiple plastic deformation for a longer time, multiple plastic deformation belongs to the mechanism of low carbon alloy steel with 9% Cr content.

Influence of the Ageing Temperature on the Selected Mechanical Properties of the Ti6Al7Nb Alloy

2015 ◽  
Vol 641 ◽  
pp. 120-123 ◽  
Author(s):  
Robert Dąbrowski ◽  
Janusz Krawczyk ◽  
Edyta Rożniata
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Volume Fraction ◽  
Heating Temperature ◽  
Ageing Temperature ◽  
Sample Length ◽  
Two Phase ◽  
Β Phase ◽  
Α Phase ◽  
The Impact

The results of investigations of the influence of the ageing temperature on the selected mechanical properties i.e. hardness, fracture toughness (examined by the linear elastic fracture mechanics - KIctest) and impact strength (KV) of two-phase Ti6Al7Nb alloy, are presented in the hereby paper. Investigations were performed in the ageing temperatures range: 450÷650°C of the alloy previously undercooled from the selected heating temperature (in two-phase range) - equal 970°C. The heating temperature was determined on the basis of the dilatometric curve of the alloy heating in the system ΔL = f ((T), where: ΔL – change of the sample length, T – temperature, which was then differentiated in the system: ΔL/ΔT = f (T). The dilatometer L78 R.I.T.A of the LINSEIS Company was used in the tests. Investigations of the alloy microstructure in the ageing temperatures range 450÷650°C were carried out by means of the light microscope Axiovert 200 MAT of the Carl Zeiss Company. It was found that nearly equiaxial grains of the primary α phase occur in the microstructure (of the volume fraction app. 30%) and that the volume fraction of the new lamellar α phase - formed from the supersaturated β phase - increases. With an increase of the alloy ageing temperature, in the mentioned above range, a small increase of its hardness from 305 to 324HV as well as a decrease of stress intensity factor KIcfrom 67.3 to 48.6 MPa x m1/2and impact strength (KV) from 40.2 to 31.3 J. The impact tests results were supplemented by the fractographic documentation. It was found, that the characteristic features of the fractures of impact test samples do not exhibit essential differences in dependence of the ageing temperature and material hardness. The fractographic investigations were performed by means of the scanning electron microscope NovaNanoSEM 450.

Effect of the metal base structure on the impact ductility of malleable and high-tensile cast irons

1988 ◽  
Vol 30 (4) ◽  
pp. 276-277
Author(s):  
V. I. Ovchinnikov ◽  
N. A. Umerenkova ◽  
V. A. Sharkov
Keyword(s):  
Cast Irons ◽  
Metal Base ◽  
The Impact ◽  
Impact Ductility ◽  
Base Structure

Diamond Tools Matrix Composites of Co Replaced by Fe with Doping Rare Earth

2012 ◽  
Vol 424-425 ◽  
pp. 848-851 ◽  
Author(s):  
Qing Hua Zou
Keyword(s):  
Rare Earth ◽  
Bending Strength ◽  
Service Performance ◽  
Rare Earth Doping ◽  
Matrix Composites ◽  
Metal Powders ◽  
Diamond Tools ◽  
Process Route ◽  
The Impact ◽  
Impact Ductility

The experiment on adding rare earth elements doped in diamond matrix composites is made. Based on the doping of rare earth in metal powders including tungsten carbide, iron and nickel, Co is entirely replaced by Fe with rare earth in diamond matrix composites, and the process route of rare earth doping is indicated. The related performance of is measured, and the results obtained show that the bending strength, the hardness and the impact ductility of Fe matrix composites with rare earth are improved. The practical service performance of Fe matrix composites with rare earth has reached up to the practical service performance of Co matrix, and bearing good practical service performance, low price, have made corresponding diamond tools.

The Effect of Metallic Addition on Mechanical Property of Aluminum (LM6) Alloy

2013 ◽  
Vol 465-466 ◽  
pp. 958-961 ◽  
Author(s):  
Roslee Ahmad ◽  
M.B.A. Asmael ◽  
R. Sadeghi ◽  
H. Mohamad ◽  
Z. Harun ◽  
...  
Keyword(s):  
Base Alloy ◽  
The Other ◽  
Cast Aluminum ◽  
Alloying Element ◽  
Cr Content ◽  
Fe Intermetallics ◽  
As Stress ◽  
The Impact ◽  
Stress Raisers ◽  
General Reduction

This article investigates the effects of addition of alloying element on the impact toughness of as-cast aluminum (LM6) alloy. Presence of 0.1 wt.% Cr increases the toughness up to 38%. In fact the sharp tips Fe intermetallics which have needle shape act as stress raisers with a general reduction of the ductility and ultimate tensile strength. On the other hand by increasing the Cr content in the base alloy the size distribution of the compounds becomes more spread. Therefore addition of Cr improves toughness impact by two mechanisms. First eliminating harmful β-intermetallics and second providing microstructure with more spread particles.

Effect of Thermal Aging on Microstructural Evolution in Ferrite of Duplex Stainless Steel in Nuclear Power Plant Applications

2017 ◽  
Vol 898 ◽  
pp. 818-825
Author(s):  
B. Zhang ◽  
F. Xue ◽  
S.L. Li ◽  
Xi Tao Wang ◽  
N.N. Liang ◽  
...  
Keyword(s):  
Aging Time ◽  
Thermal Aging ◽  
Atom Probe Tomography ◽  
Nuclear Power ◽  
Impact Test ◽  
Atom Probe ◽  
Nanoindentation Test ◽  
Α Phase ◽  
The Impact ◽  
Duplex Steels

Z3CN20-09M duplex steels are thermally aged at 400oC for up to 20,000 h. The mechanical properties have been characterized by Charpy V-notch impact test and nanoindentation test. It is found that the nanohardness in ferrite increases and the impact toughness decreases with aging time. Moreover, the distribution of alloying elements has been carefully characterized using atom probe tomography (APT). The results indicate that the ferrite decomposes into Cr-rich α' and Cr-lean α phase during the thermal aging and Ni-rich G-phase forms in ferrite. The effect of aging time on solute nanostructure has been investigated systematically.

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