Effect of Sodium Exposure On the Mechanical Properties of Zirconium

CORROSION ◽  
1961 ◽  
Vol 17 (1) ◽  
pp. 31t-34t ◽  
Author(s):  
J. C. BOKROS
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Tensile Properties ◽  
High Temperatures ◽  
Low Temperatures ◽  
Hydrogen Absorption ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Surface Oxide ◽  
The Other

Abstract It was found that surface oxide which developed on zirconium in impure sodium significantly lowered the fatigue life at elevated temperatures. Hydrogen absorption, on the other hand, had little effect on the fatigue life at elevated temperatures but lowered the fatigue life at room temperature. Also, critical recrystallization which occurred above 950 F in zirconium (a phenomenon unrelated to the presence of sodium) reduced the fatigue life at elevated as well as low temperatures. The effects attributable to sodium (i.e., the formation of surface oxide and absorption of reasonable amounts of hydrogen), did not significantly alter the tensile properties of zirconium at high temperatures. 6.3.20, 4.7, 3.5.8, 3.2.3

Effect of Nd on Microstructures and Properties of AZ31 Wrought Mg Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 301-304
Author(s):  
Wei Qiu ◽  
En Hou Han ◽  
Lu Liu
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Mg Alloys ◽  
The Other ◽  
Mg Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructures And Mechanical Properties ◽  
Re Elements

Addition of RE elements to Al-containing Mg alloys can improve properties of Mg alloys at elevated temperatures. In the present investigation, hot-extruded AZ31+x%Nd. (x=0.1,0.3,0.6and1.0 wt%) wrought Mg alloy were prepared .The effects of Nd on microstructures and mechanical properties at room temperature of new alloy were investigated. The investigation found that Nd can bring about two kind of precipitation phases . One is AlNd phase, the other is AlNdMn phase, which were identified as Al11Nd3 and Al8NdMn4 by X-ray diffraction and TEM.

Formability of Mg-Zn-Zr Based Alloy Sheets at Elevated Temperatures

2007 ◽  
Vol 345-346 ◽  
pp. 21-24
Author(s):  
Jeong Min Kim ◽  
Bong Koo Park ◽  
Joong Hwan Jun ◽  
Ki Tae Kim ◽  
Woon Jae Jung
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Experimental Results ◽  
Alloying Elements ◽  
Mechanical Process ◽  
Microstructure And Mechanical Properties ◽  
Bend Tests

Mg-3%Zn-0.2%Zr based alloy sheets with various alloying elements additions were fabricated through thermo-mechanical process, and their microstructure and mechanical properties were investigated at room and elevated temperatures. CCV(conical cup value) and V-bend tests were also carried out to evaluate the formability of the fabricated alloy sheets. The experimental results showed that small amounts of Sn or Sr additions could improve the elongation at elevated temperatures, even though the room temperature tensile properties were slightly deteriorated by the Sr addition.

Titanium Boride in High Nb Containing TiAl Alloy: Morphology and Effect on Mechanical Properties

2011 ◽  
Vol 415-417 ◽  
pp. 1121-1126
Author(s):  
Xiang Jun Xu ◽  
Jun Pin Lin ◽  
Yan Li Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Room Temperature ◽  
Tial Alloy ◽  
Cast Alloy ◽  
Harmful Effect ◽  
Titanium Boride ◽  
Creep Properties

The morphology of titanium boride in as-cast and as-forged Ti-45Al-8.5Nb-(W, B, Y) alloy containing 0.2at. % boron and the effect of borides on tensile and creep properties of the alloy are investigated. The results show that in as-cast alloy the morphology of boride appears mainly convoluted ribbons with some flakes and particles. With the extent of forging increases, the length of the ribbons decreases and their distribution is more uniform. The long ribbon in as-cast alloy is detrimental to tensile properties at both room temperature (RT) and high temperatures. The short ribbon in as-forged alloy is not harmful to RT tensile properties, but is harmful to tensile and creep properties at high temperatures. The harmful effect of the boride is due to the strain incompatibility of boride and matrix, which causes many cavities at boride/matrix boundaries and results in ultimate fracture.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

CF8C-PLUS

Alloy Digest ◽  
2008 ◽  
Vol 57 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Properties ◽  
High Temperatures

Abstract CF8C-Plus is an austenitic casting grade similar to CF8C, but with improved chemistry to stay fully austenitic at high temperatures and thus retain good mechanical properties. This datasheet provides information on composition, microstructureand tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on casting and joining. Filing Code: SS-1006. Producer or source: Caterpillar Technical Center.

On the use of Ozawa/Flynn/Wall method to determine aging activation energy for elastomers

2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Dwell Time ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Degradation Mechanism ◽  
Kinetics Of ◽  
Wall Method

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.

Newly Developed Heat Resistant Magnesium Alloy by Thixomolding®

2005 ◽  
Vol 488-489 ◽  
pp. 287-290 ◽  
Author(s):  
Tadayoshi Tsukeda ◽  
Ken Saito ◽  
Mayumi Suzuki ◽  
Junichi Koike ◽  
Kouichi Maruyama
Keyword(s):  
Aluminum Alloy ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Die Casting ◽  
The Other ◽  
Heat Resistant ◽  
Higher Temperature ◽  
Better Than

We compared the newly developed heat resistant magnesium alloy with conventional ones by Thixomolding® and aluminum alloy by die casting. Tensile properties at elevated temperatures of AXEJ6310 were equal to those of ADC12. In particular, elongation tendency of AXEJ6310 at higher temperature was better than those of the other alloys. Creep resistance of AXEJ6310 was larger than that of AE42 by almost 3 orders and smaller than that of ADC12 by almost 2 orders of magnitude. Fatigue limits at room temperature and 423K of AXEJ6310 was superior among conventional magnesium alloys.

scholarly journals Comparison of Mechanical and Microstructural Properties of as-Cast Al-Cu-Mg-Ag Alloys: Room Temperature vs. High Temperature

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1330
Author(s):  
Muhammad Farzik Ijaz ◽  
Mahmoud S. Soliman ◽  
Ahmed S. Alasmari ◽  
Adel T. Abbas ◽  
Faraz Hussain Hashmi
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Mechanical Testing ◽  
Tensile Testing ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Microstructural Properties ◽  
Testing Environments ◽  
Mechanical And Microstructural Properties ◽  
Mg Content

Unfolding the structure–property linkages between the mechanical performance and microstructural characteristics could be an attractive pathway to develop new single- and polycrystalline Al-based alloys to achieve ambitious high strength and fuel economy goals. A lot of polycrystalline as-cast Al-Cu-Mg-Ag alloy systems fabricated by conventional casting techniques have been reported to date. However, no one has reported a comparison of mechanical and microstructural properties that simultaneously incorporates the effects of both alloy chemistry and mechanical testing environments for the as-cast Al-Cu-Mg-Ag alloy systems. This preliminary prospective paper presents the examined experimental results of two alloys (denoted Alloy 1 and Alloy 2), with constant Cu content of ~3 wt.%, Cu/Mg ratios of 12.60 and 6.30, and a constant Ag of 0.65 wt.%, and correlates the synergistic comparison of mechanical properties at room and elevated temperatures. According to experimental results, the effect of the precipitation state and the mechanical properties showed strong dependence on the composition and testing environments for peak-aged, heat-treated specimens. In the room-temperature mechanical testing scenario, the higher Cu/Mg ratio alloy with Mg content of 0.23 wt.% (Alloy 1) possessed higher ultimate tensile strength when compared to the low Cu/Mg ratio with Mg content of 0.47 wt.% (Alloy 2). From phase constitution analysis, it is inferred that the increase in strength for Alloy 1 under room-temperature tensile testing is mainly ascribable to the small grain size and fine and uniform distribution of θ precipitates, which provided a barrier to slip by deaccelerating the dislocation movement in the room-temperature environment. Meanwhile, Alloy 2 showed significantly less degradation of mechanical strength under high-temperature tensile testing. Indeed, in most cases, low Cu/Mg ratios had a strong influence on the copious precipitation of thermally stable omega phase, which is known to be a major strengthening phase at elevated temperatures in the Al-Cu-Mg-Ag alloying system. Consequently, it is rationally suggested that in the high-temperature testing scenario, the improvement in mechanical and/or thermal stability in the case of the Alloy 2 specimen was mainly due to its compositional design.

scholarly journals The principal magnetic susceptibilities of neodymium sulphate octahydrate at low temperatures

1939 ◽  
Vol 170 (941) ◽  
pp. 266-271 ◽  
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Energy Levels ◽  
Constant Factor ◽  
The Other ◽  
Crystalline Field ◽  
Cubic Symmetry ◽  
The Subject ◽  
The Difference ◽  
The One

The magnetic and other related properties of neodymium sulphate have been the subject of numerous investigations in recent years, but there is still a remarkable conflict of evidence on all the essential points. The two available determinations of the susceptibility of the powdered salt at low temperatures, those of Gorter and de Haas (1931) from 290 to 14° K and of Selwood (1933) from 343 to 83° K both fit the expression X ( T + 45) = constant over the range of temperature common to both, but the constants are not the same and the susceptibilities at room temperature differ by 11%. The fact that the two sets of results can be converted the one into the other by multiplying throughout by a constant factor suggested that the difference in the observed susceptibilities was due to some error of calibration. It could, however, also be due to the different purity of the samples examined though the explanation of the occurrence of the constant factor is then by no means obvious. From their analysis of the absorption spectrum of crystals of neodymium sulphate octahydrate Spedding and others (1937) conclude that the crystalline field around the Nd+++ ion is predominantly cubic in character since they find three energy levels at 0, 77 and 260 cm. -1 .* Calculations of the susceptibility from these levels reproduce Selwood’s value at room temperature but give no agreement with the observations-at other temperatures. On the other hand, Penney and Schlapp (1932) have shown that Gorter and de Haas’s results fit well on the curve calculated for a crystalline field of cubic symmetry and such a strength that the resultant three levels lie at 0, 238 and 834 cm. -1 , an overall spacing almost three times as great as Spedding’s.

Influence of High Temperatures on the Mechanical Properties of Wood Bio-Concretes

2022 ◽  
Author(s):  
Amanda Lorena Dantas Aguiar ◽  
M’hamed Yassin Rajiv da Gloria ◽  
Romildo Dias Toledo Filho
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperatures ◽  
Room Temperature ◽  
Plant Biomass ◽  
Compression Tests ◽  
Wood Degradation ◽  
Cementitious Matrix ◽  
Wood Shavings ◽  
Temperature Reference

The use of wood wastes in the production of bio-concrete shows high potential for the development of sustainable civil construction, since this material, in addition to having low density, increases the energy efficiency of buildings in terms of thermal insulation. However, a concern arising from the production of bio-concretes with high amounts of plant biomass is how this material behaves when subjected to high temperatures. Therefore, this work aims to evaluate the influence of high temperatures on the mechanical properties of wood bio-concretes. The mixtures were produced with wood shavings volumetric fractions of 40, 50 and 60% and cementitious matrix composed of a combination of cement, fly ash and metakaolin. Uniaxial compression tests and scanning electron microscopy (SEM) were performed, with bio-concrete at age of 28 days, at room temperature (reference) and after exposure to temperatures of 100, 150, 200 and 250 °C. The density and compressive strength of the bio-concrete gradually decreased with increasing biomass content. Up to 200 °C, reductions in strength and densities less than 19% and 13%, respectively, were observed. At 250 °C, reductions of compressive strength reached 87%. Analysis performed by SEM showed an increase in the number of cracks in the wood-cementitious matrix interface and wood degradation by increasing the temperature.

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