Fatigue of Microlithographically-Patterned Free-Standing Aluminum Thin Film Under Axial Stresses

1995 ◽  
Vol 117 (1) ◽  
pp. 1-6 ◽  
Author(s):  
David T. Read ◽  
James W. Dally
Keyword(s):  
Thin Film ◽  
Fatigue Life ◽  
Ultimate Strength ◽  
Upper Bound ◽  
Cyclic Stress ◽  
Free Standing ◽  
Titanium Thin Film ◽  
Titanium Aluminum ◽  
Stress Cycles ◽  
Repeated Cycling

Fatigue life as a function of number of stress cycles has been determined for three-layer titanium-aluminum-titanium thin-film specimens. For nominal stresses ranging from 50 to 90 percent of the upper-bound ultimate strength, the fatigue lives ranged up to 76 cycles. In all specimens, active cracks were observed after only a few stress cycles. These cracks grew with repeated cycling. The fatigue life was reached when the specimen could no longer sustain the maximum cyclic stress.

Compressive Fatigue of a Plasma Sprayed Zr02-8 wt%Y203 and Zr02-10wt%NiCrAlCoY TTBC

1995 ◽  
Vol 117 (3) ◽  
pp. 305-310 ◽  
Author(s):  
B. P. Johnsen ◽  
T. A. Cruse ◽  
R. A. Miller ◽  
W. J. Brindley
Keyword(s):  
Compressive Strength ◽  
Fatigue Life ◽  
Elevated Temperatures ◽  
Cyclic Hardening ◽  
Cyclic Stress ◽  
Free Standing ◽  
Initial Portion ◽  
Base Materials ◽  
Plasma Sprayed ◽  
Tubular Specimens

High cycle (>106 cycles) fatigue (HCF) behavior of thick thermal barrier coatings (TTBC’s) was examined for applied stresses near the compressive strength of the material. Test data were obtained on four coating systems: two base materials in the unsealed and CrO2 dip sealed conditions. Free standing tubular specimens were evaluated. The data show that compressive fatigue limits exist for the four coating systems at room temperature (RT) and sealing with CrO2 improves RT fatigue life. Test results also show the ratio of the peak cyclic stress, at 105 cycles, to ultimate compressive strength (UCS) of the Yttria Stabilized Zirconia (YSZ) tubular specimens approaches 0.90 at R = 0.6 (R = minimum/maximum compressive stress). Residual UCS increases were observed after fatigue run-outs at elevated temperatures (5 at 700°C and 1 at 400°C) for both YSZ and the cermet. Ratchetting with cyclic hardening was observed during fatigue with deformation occurring primarily in the initial portion of the high cycle fatigue life of the specimens.

scholarly journals Oxidation of boron-titanium thin film coating during cyclic tests on thermal shock

2020 ◽  
Vol 1005 ◽  
pp. 012006
Author(s):  
E E Suslov ◽  
A S Larionov ◽  
S B Kislitsin ◽  
I I Chernov ◽  
M S Staltsov ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Shock ◽  
Film Coating ◽  
Cyclic Tests ◽  
Thin Film Coating ◽  
Titanium Thin Film

A Self‐Limited Free‐Standing Sulfide Electrolyte Thin Film for All‐Solid‐State Lithium Metal Batteries

2021 ◽  
pp. 2101985
Author(s):  
Gao‐Long Zhu ◽  
Chen‐Zi Zhao ◽  
Hong‐Jie Peng ◽  
Hong Yuan ◽  
Jiang‐Kui Hu ◽  
...  
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Lithium Metal ◽  
Free Standing ◽  
Lithium Metal Batteries

scholarly journals Effect of Mean Stress on the Fatigue Life Prediction of Notched Fiber-Reinforced 2060 Al-Li Alloy Laminates under Spectrum Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Weiying Meng ◽  
Liyang Xie ◽  
Yu Zhang ◽  
Yawen Wang ◽  
Xiaofang Sun ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Linear Model ◽  
Life Prediction ◽  
Piecewise Linear ◽  
Forecast Accuracy ◽  
Cyclic Stress ◽  
Fatigue Life Prediction ◽  
Fiber Reinforced ◽  
Piecewise Linear Model ◽  
Spectrum Loading

This paper presents a study on the fatigue life prediction of notched fiber-reinforced 2060 Al-Li alloy laminates under spectrum loading by applying the constant life diagram. Firstly, a review on the state of the art of constant life diagram models for the life prediction of composite materials is given, which highlights the effect on the forecast accuracy. Then, the fatigue life of notched fiber-reinforced Al-Li alloy laminates (2/1 laminates and 3/2 laminates) is tested under cyclic stress, which has different stress cycle characteristics (constant amplitude loading and Mini-Twist spectrum loading). The introduced models are successfully realized based on the available experimental data of examined laminates. In the case of Mini-Twist spectrum loading, the effect of the constant life diagram on the life prediction accuracy of examined laminates is studied based on the rainflow-counting method and Miner damage criteria. The results show that the simple Goodman model and piecewise linear model have certain advantages compared to other complex models for the life prediction of notched fiber metal laminates with different structures under Mini-Twist loading. From the engineering perspective, the S-N curve prediction based on the piecewise linear model is most applicable and accurate among all the models.

scholarly journals CVD and PVD coating process modelling by using artificial neural networks

2012 ◽  
Vol 1 (1) ◽  
pp. 46 ◽  
Author(s):  
Amir Mahyar Khorasani ◽  
Mohammad Reza Solymany yazdi ◽  
Mehdi Faraji ◽  
Alex Kootsookos
Keyword(s):  
Thin Film ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Chemical Vapor ◽  
Film Coating ◽  
Deposition Process ◽  
Thin Film Coating ◽  
Mlp Neural Network ◽  
Titanium Thin Film ◽  
Pvd Coating

Thin-film coating plays a prominent role on the manufacture of many industrial devices. Coating can increase material performance due to the deposition process. Having adequate and precise model that can predict the hardness of PVD and CVD processes is so helpful for manufacturers and engineers to choose suitable parameters in order to obtain the best hardness and decreasing cost and time of industrial productions. This paper proposes the estimation of hardness of titanium thin-film layers as protective industrial tools by using multi-layer perceptron (MLP) neural network. Based on the experimental data that was obtained during the process of chemical vapor deposition (CVD) and physical vapor deposition (PVD), the modeling of the coating variables for predicting hardness of titanium thin-film layers, is performed. Then, the obtained results are experimentally verified and very accurate outcomes had been attained.

The Elastic Moduli of Silver Thin Films Measured with a New Microtensile Tester

1991 ◽  
Vol 239 ◽  
Author(s):  
J. Ruud ◽  
D. Josell ◽  
A. L. Greer ◽  
F. Spaepen
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Diffraction Grating ◽  
Strain Measurement ◽  
Elastic Moduli ◽  
Two Dimensional ◽  
Bulk Crystals ◽  
Free Standing ◽  
Tensile Direction ◽  
Silver Thin Films

ABSTRACTA new design for a thin film microtensile tester is presented. The strain is measured directly on the free-standing thin film from the displacement of laser spots diffracted from a thin grating applied to its surface by photolithography. The diffraction grating is two-dimensional, allowing strain measurement both along and transverse to the tensile direction. In principle, both Young's modulus and Poisson's ratio of a thin film can be determined. Ag thin films with strong <111> texture were tested. The measured Young moduli agreed with those measured on bulk crystals, but the measured Poisson ratios were low, most likely due to slight transverse folding of the film that developed during the test.

Fatigue Life Prediction of Drill-String Subjected to Random Loadings

2014 ◽  
Author(s):  
Jiahao Zheng ◽  
Hongyuan Qiu ◽  
Jianming Yang ◽  
Stephen Butt
Keyword(s):  
Fatigue Life ◽  
Time History ◽  
Beam Theory ◽  
Drill String ◽  
Finite Element Models ◽  
Bernoulli Beam ◽  
Stress Cycles ◽  
Rainflow Counting ◽  
Euler Bernoulli Beam ◽  
Random Nature

Based on linear damage accumulation law, this paper investigates the fatigue problem of drill-strings in time domain. Rainflow algorithms are developed to count the stress cycles. The stress within the drill-string is calculated with finite element models which is developed using Euler-Bernoulli beam theory. Both deterministic and random excitations to the drill-string system are taken into account. With this model, the stress time history in random nature at any location of the drill-string can be obtained by solving the random dynamic model of the drill-string. Then the random time history is analyzed using rainflow counting method. The fatigue life of the drill-string under both deterministic and random excitations can therefore be predicted.

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