High Temperature Mechanical Properties of Al2O3/ZrO2(Y2O3)Fibers

1994 ◽  
Vol 365 ◽  
Author(s):  
A. Sayir ◽  
S. C. Farmer ◽  
P. O. Dickerson ◽  
H. M. Yun
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Single Crystal ◽  
Creep Resistance ◽  
Directionally Solidified ◽  
Two Phase ◽  
High Temperature Mechanical Properties ◽  
Crystal Fibers ◽  
High Temperature Tensile ◽  
Laser Heated

ABSTRACTIn-situ composite fibers produced by directional solidification of two phase oxide eutectics are one means of producing fibers with good strength and higher creep resistance than single crystal fibers. In this work, directionally solidified alumina-yttria stabilized zirconia eutectic fibers have been grown by the laser heated float zone (LHFZ) method at NASA Lewis. The average tensile strength of the alumina-zirconia (60.8 m/o Al2O3; 39.2 m/o ZrO2 (9.5 m/o Y2O3)) eutectic fibers was 1.2 GPa at room temperature. The high temperature tensile strength and creep resistance of the eutectic fiber were determined and compared to single crystal Al2O3.

Microstructure and High Temperature Properties of 85% Al2O3-15% SiO2 Fibers

1994 ◽  
Vol 350 ◽  
Author(s):  
D. M. Wilson ◽  
S. L. Lieder ◽  
D. C. Lueneburg
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Sol Gel ◽  
Two Phase ◽  
Single Filament ◽  
Polycrystalline Alumina ◽  
Creep Properties ◽  
High Temperature Properties ◽  
Alumina Fibers ◽  
High Temperature Tensile

AbstractA new sol/gel fiber which exhibits exceptional high temperature properties was recently developed at 3M. This fiber has the composition 85% Al2O3-15% SiO2 (85A-15S). High temperature tensile strength and creep properties were measured in the temperature range 1000°C – 1300°C. The creep rate for the 85A-15S fibers was three orders of magnitude less than single phase polycrystalline alumina fibers such as Nextel 610, and 90% of room tensile strength was retained at 1250°C. These exceptional high temperature properties were attributed to a unique, two-phase microstructure consisting of globular and elongated grains of a-Al2O3 and mullite (3Al2O3-2SiO2). The room temperature single filament strength of the 85% Al2O3-15% SiO2 fibers was 2130 MPa, and the elastic modulus was 260 GPa.

scholarly journals The Effect of the Cooling Rates on the Microstructure and High-Temperature Mechanical Properties of a Nickel-Based Single Crystal Superalloy

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4256
Author(s):  
Xiao-Yan Wang ◽  
Meng Li ◽  
Zhi-Xun Wen
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Single Crystal ◽  
Solution Treatment ◽  
Single Crystal Superalloy ◽  
Air Cooling ◽  
Strengthening Effect ◽  
Cooling Rates ◽  
High Temperature Mechanical Properties ◽  
High Temperature Tensile

The as-cast alloy of nickel-based single-crystal superalloy was used as the research object. After four hours of solution treatment at 1315 °C, four cooling rates (water cooling (WC), air cooling (AC) and furnace cooling (FC1/FC2)) were used to reduce the alloy to room temperature. Four different microstructures of nickel-based superalloy material were prepared. A high-temperature tensile test at 980 °C was carried out to study the influence of various rates on the formation of the material’s microstructure and to further obtain the influence of different microstructures on the high-temperature mechanical properties of the materials. The results show that an increase of cooling rate resulted in a larger γ′ phase nucleation rate, formation of a smaller γ′ phase and a greater number. When air cooling was used, the uniformity of the γ′ phase and the coherence relationship between the γ′ phase and the γ phase were the best. At the same time, the test alloy had the best high-temperature tensile properties, and the material showed a certain degree of plasticity. TEM test results showed that the test alloy mainly blocked dislocations from traveling in the material through the strengthening effect of γ′, and that AC had the strongest hindering effect on γ′ dislocation movement.

The Effects of Nb and Cr Addition on Mechanical and Chemical Properties of Cold-Rolled Ni3(Si,Ti) Intermetallic Foils

2007 ◽  
Vol 561-565 ◽  
pp. 411-414 ◽  
Author(s):  
Yasuyuki Kaneno ◽  
Takayuki Takasugi
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Room Temperature ◽  
Chemical Properties ◽  
Solid Solution Phase ◽  
Two Phase ◽  
Thermomechanical Process ◽  
Thin Foils ◽  
Cold Rolled ◽  
High Temperature Tensile

Nb and/or Cr added Ni3(Si,Ti) as well as unalloyed Ni3(Si,Ti) intermetallic thin foils (i.e., Ni3(Si,Ti), Ni3(Si,Ti)+Nb, Ni3(Si,Ti)+Cr and Ni3(Si,Ti)+Nb,Cr) were fabricated from arc-melted polycrystalline ingots by thermomechanical process and subsequent heavy cold-rolling. Tensile property at room temperature as well as at high temperature and oxidization behavior of the cold-rolled foils with a thickness of ~200μm were investigated. The Ni3(Si,Ti) and Ni3(Si,Ti)+Nb alloys showed a single-phase microstructure consisting of L12 phase, while the Ni3(Si,Ti)+Cr and Ni3(Si,Ti)+Nb,Cr alloys exhibited a two-phase microstructure with A1 (fcc) Ni solid solution phase within the L12 grains. All the cold-rolled foils showed high tensile strength (over 2GPa) at room temperature although no plastic elongation was observed. The addition of Nb and/or Cr slightly enhanced the room-temperature tensile strength of the Ni3(Si,Ti) alloy. On the other hand, the addition of Nb and/or Cr prominently enhanced high-temperature tensile strength as well as oxidization resistance, while the addition of Cr improved high-temperature elongation.

HIGH-TEMPERATURE TENSILE STRENGTH DETERMINATION OF SINGLE CRYSTAL ALUMINA FIBERS

2014 ◽  
Vol 0 (4) ◽  
pp. 3-3 ◽  
Author(s):  
O.V. Basargin ◽  
◽  
T.M. Scheglova ◽  
V.J. Nikitina ◽  
V.I. Svistunov ◽  
...  
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Single Crystal ◽  
Strength Determination ◽  
Alumina Fibers ◽  
High Temperature Tensile

The Effects of Laser Shock Peening on the Heat Resistance Property of A356 Aluminum Alloy

2013 ◽  
Vol 675 ◽  
pp. 213-218
Author(s):  
Bin Fan ◽  
Ji Wen Fan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Temperature ◽  
Compressive Stress ◽  
Tensile Tests ◽  
Residual Compressive Stress ◽  
Laser Shock ◽  
High Temperature Mechanical Properties ◽  
High Level ◽  
High Temperature Tensile

Laser shocking peening (LSP) is a good way to improving mechanical properties. The influence of laser shock peeening on the high temperature mechanical properties were studied by investigating the thermal stability of residual compressive stress induced by LSP and high temperature tensile properties. The samples treated by LSP were placed in annealing oven and insulated for 60mins under 200°C. The high temperature tensile tests were did on the MTS machine, the temperatures were 250°C. The results showed that the compressive residual stress induced by LSP were only released 19.7%, the residual compressive stress still remained at a high level, about-125.45MPa; the results from the high temperature tensile tests shows LSP can improved the elevated temperature tensile strength, the ultimate tensile strength（UTS） of LSP was from 319.79MPa to 252.63MPa，decreased 21%, but the UTS of untreated by LSP was from 283MPa to 130.18MPa，released 46.1%.

scholarly journals Microstructure and High Temperature Tensile Properties of Mg–10Gd–5Y–0.5Zr Alloy after Thermo-Mechanical Processing

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 980 ◽  
Author(s):  
Guohua Wu ◽  
H. Jafari Nodooshan ◽  
Xiaoqin Zeng ◽  
Wencai Liu ◽  
Dejiang Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Temperature ◽  
Tensile Properties ◽  
Test Temperature ◽  
Mechanical Processing ◽  
Twin Boundaries ◽  
High Temperature Mechanical Properties ◽  
High Temperature Tensile ◽  
High Temperature Tensile Properties

The microstructure, high-temperature tensile properties and fracture behavior of the Mg-10Gd-5Y-0.5Zr alloy after thermo-mechanical processing (pre-tension between solution and aging treatment) were investigated. The pre-deformed alloy shows the accelerated aging kinetics compared to the un-deformed alloy. Microstructure of pre-deformed samples showed not only the homogeneous nucleation of the precipitate but also heterogeneous nucleation of precipitates on the dislocation and twin boundaries. Tensile results show that the pre-deformation enhanced the strength of the alloy, while it deteriorates the ductility of the alloy. The ultimate tensile strength (UTS) of the T6 treated un-deformed and pre-deformed alloy at room temperature are 331 MPa and 366 MPa, respectively. Tensile strength of the T6 treated alloy in both un-deformed and deformed conditions was enhanced by raising the test temperature and then reduced by further raising the test temperature. The higher strength of the pre-deformed alloy could be related to the higher density of the precipitates, which grow on the twin boundaries and can hinder the dislocation movement and strengthen the alloy. The results shows that thermo-mechanical processing can significantly improve the room- and high-temperature mechanical properties and enhance the formation of precipitates in Mg-10Gd-5Y-0.5Zr alloy, which can lead to wider application of the alloy in industries such as aerospace or powertrains that need better room- and high-temperature mechanical properties.

Effects of Si, Cu and Mg on the High-Temperature Mechanical Properties of Al-Si-Cu-Mg Alloy

2013 ◽  
Vol 652-654 ◽  
pp. 1030-1034 ◽  
Author(s):  
Wen Da Zhang ◽  
Jing Yang ◽  
Jing Zhi Dang ◽  
Yun Liu ◽  
Hong Xu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Temperature ◽  
Initial Crack ◽  
Elongation Rate ◽  
Mg Alloy ◽  
High Temperature Mechanical Properties ◽  
High Temperature Tensile ◽  
The Relationship ◽  
Scanning Electron

The regression equation of the relationship between Si, Cu and Mg and the mechanical properties of Al-Si-Cu-Mg alloy was established according to the orthogonal experimental results. The microstructure of the Al-Si-Cu-Mg alloy was analyzed with scanning electron microscopy and energy dispersive spectroscopy. The results show that Si, Cu and Mg affected the mechanical properties (tensile strength and elongation rate) at 250 °C most significantly, minimally and negatively, respectively. The interactions between Cu, Mg and Si greatly reduced the high-temperature tensile strength owing to the formation of brittle and hard intermetallic Al5Mg8Cu2Si6 that behaved as the initial crack during stretching.

scholarly journals The Influence of La and Ce on Microstructure and Mechanical Properties of an Al-Si-Cu-Mg-Fe Alloy at High Temperature

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 384
Author(s):  
Andong Du ◽  
Anders E. W. Jarfors ◽  
Jinchuan Zheng ◽  
Kaikun Wang ◽  
Gegang Yu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Temperature ◽  
Intermetallic Phases ◽  
High Temperature Strength ◽  
Thermal Expansion Mismatch ◽  
Strengthening Mechanisms ◽  
High Temperature Mechanical Properties ◽  
Minor Contribution ◽  
A Minor

The effect of lanthanum (La)+cerium (Ce) addition on the high-temperature strength of an aluminum (Al)–silicon (Si)–copper (Cu)–magnesium (Mg)–iron (Fe)–manganese (Mn) alloy was investigated. A great number of plate-like intermetallics, Al11(Ce, La)3- and blocky α-Al15(Fe, Mn)3Si2-precipitates, were observed. The results showed that the high-temperature mechanical properties depended strongly on the amount and morphology of the intermetallic phases formed. The precipitated tiny Al11(Ce, La)3 and α-Al15(Fe, Mn)3Si2 both contributed to the high-temperature mechanical properties, especially at 300 °C and 400 °C. The formation of coarse plate-like Al11(Ce, La)3, at the highest (Ce-La) additions, reduced the mechanical properties at (≤300) ℃ and improved the properties at 400 ℃. Analysis of the strengthening mechanisms revealed that the load-bearing mechanism was the main contributing mechanism with no contribution from thermal-expansion mismatch effects. Strain hardening had a minor contribution to the tensile strength at high-temperature.

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