Notch Sensitivity, Mechanical, and Microstructural Characteristics of TD-NiCr at Elevated Temperatures

1974 ◽  
Vol 96 (2) ◽  
pp. 109-114 ◽  
Author(s):  
D. J. Wilson ◽  
A. Ferrari
Keyword(s):  
Inconel 718 ◽  
Mechanical Characteristics ◽  
Elevated Temperatures ◽  
Time Dependent ◽  
Notch Sensitivity ◽  
Microstructural Characteristics ◽  
Notched Specimen ◽  
Theoretical Concepts ◽  
Notched Specimens ◽  
Good Agreement

Tensile and creep-rupture tests were conducted for smooth and sharp edge-notched specimens of 0.015-in. (0.38 mm) thick TD-NiCr sheet at 1000 to 1800 deg F (538–982 deg C). The dislocation mechanisms operative were in good agreement with theoretical concepts. Time-dependent notch sensitivity was not observed. The notched specimen behavior correlated with the same mechanical characteristics and microstructural features as previously established for Waspaloy and Inconel 718 which are strengthened by coherent precipitates.

scholarly journals Relationship of Mechanical Characteristics and Microstructural Features to the Time-Dependent Edge-Notch Sensitivity of Inconel 718 Sheet

1973 ◽  
Vol 95 (2) ◽  
pp. 112-123 ◽  
Author(s):  
D. J. Wilson
Keyword(s):  
Inconel 718 ◽  
Mechanical Characteristics ◽  
Rupture Life ◽  
Dislocation Motion ◽  
Time Dependent ◽  
Notch Sensitivity ◽  
Motion Mechanism ◽  
Notched Specimens ◽  
Edge Notch ◽  
Relationship Of

Time-dependent notch sensitivity of Inconel 718 sheet was observed at 900 deg F to 1200 deg F (482–649 deg C). It occurred when edge-notched specimens were loaded below the yield strength and smooth specimen tests showed that small amounts of creep consumed large rupture life fractions. The severity of the notch sensitivity was reduced by decreasing the temperature of the solution treatments, increasing the time and/or temperature of aging and increasing the test temperature to 1400 deg F (760 deg C). Elimination of time-dependent notch sensitivity correlated with a change in dislocation motion mechanism from shearing to bypassing precipitate particles.

scholarly journals Deformation Characteristics and Time-Dependent Notch Sensitivity of Udimet 700 at Intermediate Temperatures

1975 ◽  
Vol 97 (3) ◽  
pp. 223-233 ◽  
Author(s):  
D. J. Wilson
Keyword(s):  
Particle Size ◽  
Yield Strength ◽  
Average Particle Size ◽  
Time Dependent ◽  
Notch Sensitivity ◽  
Average Particle ◽  
Deformation Characteristics ◽  
Notched Specimen ◽  
Notched Specimens ◽  
Sensitive Behavior

Time-dependent notch sensitivity of Udimet 700 sheet, bar, and investment castings was observed between 1000 deg and 1400 deg F (538–760 deg C) but not at 1600 deg F (871 deg C). As was the case for Modified Waspaloy, Waspaloy, Rene´ 41, INCONEL 718 and TD-NiCr, it occurred when notched specimens were loaded below the yield strength and when creep deformation was localized. For each γ′ strengthened alloy and notched specimen geometry, a stress-average particle size zone can be defined to characterize the notch sensitive behavior.

Sensitivity of the Creep-Rupture Properties of Waspaloy Sheet to Sharp-Edged Notches in the Temperature Range 1000–1400 Deg F

1972 ◽  
Vol 94 (1) ◽  
pp. 13-21 ◽  
Author(s):  
D. J. Wilson
Keyword(s):  
Necessary Conditions ◽  
Rupture Life ◽  
Creep Rupture ◽  
Optimum Combination ◽  
Time Dependent ◽  
Notch Sensitivity ◽  
Notched Specimen ◽  
Solution Treated ◽  
Material Solution ◽  
Rupture Properties

Time-dependent notch sensitivity of Waspaloy was observed at test temperatures from 1000 to 1300 deg F. Its occurrence in this range was dependent on the heat treatment. “Overaging” eliminated the notch sensitivity. Optimum combination of smooth and notched specimen strengths for material solution treated at 1975 deg F were obtained by aging 24 hr at 1550 deg F. Necessary conditions for time-dependent notch sensitivity were (i) the notch specimen loads had to be below the approximate 0.2 percent off set yield strength; and (ii) test data from smooth specimens had to indicate that small amounts of creep used up large fractions of creep-rupture life. No reasons were evident why these criteria will not prove applicable to other alloys.

Evaluating Micro-Structure, Hydration and Thermal Expansions of Cement Containing Nano-Silica

GIS Business ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 158-165 ◽  
Author(s):  
Dr. Sarvesh PS Rajput
Keyword(s):  
Portland Cement ◽  
Mechanical Characteristics ◽  
Microstructural Properties ◽  
Nano Silica ◽  
Micro Structure ◽  
Microstructural Characteristics ◽  
Mechanical And Microstructural Properties

This study reported that the addition of nano-silica enhances the mechanical characteristics of concrete as its compressive, flexural and tensile split strengths are increased. As a comparison mixture to equate it along with nano-modified concrete, ordinary samples of Portland cement (OPC) have been utilized. Herein, upto 6.0 percent of OPC has been substituted by nanosilica. In fact, the introduction of nanosilica improves mechanical and microstructural characteristics of concrete by significantly (28 to 35%). The finding therefore, indicated that partly replacing OPC with up to 5 percent nanosilica increases the mechanical and microstructural properties cured up to ninety days as opposed to the standard OPC mix.

Numerical Simulation of Ship Collision and Validations With Experimental Results

2021 ◽  
Author(s):  
Xiangbiao Wang ◽  
Chun Bao Li ◽  
Ling Zhu
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Structural Damage ◽  
Added Mass ◽  
Ship Motion ◽  
Time Dependent ◽  
Structural Deformation ◽  
Structure Interaction ◽  
Ship Collision ◽  
Good Agreement

Abstract Ship collision accidents occur from time to time in recent years, and this would cause serious consequences such as casualties, environmental pollution, loss of cargo on board, damage to the ship and its equipment, etc. Therefore, it is of great significance to study the response of ship motion and the mechanism of structural damage during the collision. In this paper, model experiments and numerical simulation are used to study the ship-ship collision. Firstly, the Coupled Eulerian-Lagrangian (CEL) was used to simulate the fluid-structure interaction for predicting structural deformation and ship motion during the normal ship-ship collision. Meanwhile, a series of model tests were carried out to validate the numerical results. The validation presented that the CEL simulation was in good agreement with the model test. However, the CEL simulation could not present the characteristics the time-dependent added mass.

scholarly journals Energy Dependence of Total Cross Sections for Reactions with 4, 6he, 6, 7, 9li Nuclei

KnE Energy ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 21
Author(s):  
Yu Penionzhkevich ◽  
Yu Sobolev ◽  
V Samarin ◽  
M Naumenko
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Numerical Solution ◽  
Energy Dependence ◽  
Cross Sections ◽  
Beam Energy ◽  
Microscopic Analysis ◽  
Time Dependent ◽  
Total Cross Sections ◽  
Good Agreement

The paper presents the results of measurement of the total cross sections for reactions 4,6He + Si and 6,7,9Li + Si in the beam energy range 5−50 A⋅MeV. The enhancements of the total cross sections for reaction 6He + Si compared with reaction 4He + Si, and 9Li + Si compared with reactions 6,7Li + Si have been observed. The performed microscopic analysis of total cross sections for reactions 6He + Si and 9Li + Si based on numerical solution of the time-dependent Schrödinger equation for external neutrons of projectile nuclei 6He and 9Li yielded good agreement with experimental data.

Three-Dimensional Thermocapillary Convection in Open Cylindrical Annuli

2000 ◽  
Author(s):  
Bok-Cheol Sim ◽  
Abdelfattah Zebib
Keyword(s):  
Reynolds Number ◽  
Aspect Ratio ◽  
Critical Frequency ◽  
Thermocapillary Convection ◽  
Three Dimensional ◽  
Time Dependent ◽  
Infinite Layer ◽  
Aspect Ratios ◽  
Temperature Oscillations ◽  
Good Agreement

Abstract Three-dimensional, time-dependent thermocapillary convection in open cylindrical containers is investigated numerically. Results for aspect ratios (Ar) of 1, 2.5, 8, and 16 and a Prandtl number of 6.84 are obtained to compare the results of numerical simulations with ongoing experiments. Convection is steady and axisymmetric at sufficiently low values of the Reynolds number (Re). Transition to oscillatory states occurs at critical values of Re which depend on Ar. With Ar = 1.0 and 2.5, we observe, respectively, 5 and 9 azimuthal wavetrains travelling clockwise at the free surface near the critical Re. With Ar = 8.0 and 16.0, there are substantially more, but pulsating waves near the critical Re. In the case of Ar = 16.0, which approaches the conditions in an infinite layer, our results are in good agreement with linear theory. While the critical Reynolds number decreases with increasing aspect ratio in the case of azimuthal rotating waves, it increases with increasing aspect ratio in the case of azimuthal pulsating waves. The critical frequency of temperature oscillations is found to decrease linearly with increasing Ar. We have also computed supercritical time-dependent states and find that while the frequency increases with increasing Re near the critical region, the frequency of supercritical convection decreases with Re.

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