scholarly journals An Experimental Technique for the Evaluation of Strain Dependent Material Properties of Hard Coatings

2008 ◽  
Vol 15 (6) ◽  
pp. 697-712 ◽  
Author(s):  
Shad A. Reed ◽  
Anthony N. Palazotto ◽  
William P. Baker
Keyword(s):  
Hard Coatings ◽  
Surface Measurement ◽  
Magnesium Aluminate ◽  
Laser Vibrometer ◽  
Minimal Amount ◽  
Magnesium Aluminate Spinel ◽  
Damping Properties ◽  
Electromagnetic Excitation ◽  
Stiffness And Damping ◽  
Strain Dependent

A novel vibration experiment consisting of a free-free boundary condition, an electromagnetic excitation source, a vacuum chamber, and a laser vibrometer based surface measurement system has been developed that permits high levels of excitation on highly damped specimens with a minimal amount of unwanted systematic error. While some of the aspects of this experiment are not unique, when combined with a processing technique that accounts for the nonlinearities present in the system, this experiment permits, accurate measurement of strain dependent stiffness and damping properties of hard coatings at high strain levels. This procedure has been demonstrated using a titanium beam that has been coated with a free-layer damping treatment of Magnesium Aluminate Spinel. The results indicate that Magnesium Aluminate Spinel has both nonlinear stiffness and damping properties. The stiffness asymptotes to a minimum value around 650 microstrain while the damping is a maximum around 100 microstrain. Additionally, the data contained herein cover a larger strain range for this material than previously reported.

scholarly journals Synthesis and characterization of a new ZIF-67@MgAl2O4 nanocomposite and its adsorption behaviour

RSC Advances ◽  
2021 ◽  
Vol 11 (22) ◽  
pp. 13245-13255
Author(s):  
Mehdi Davoodi ◽  
Fatemeh Davar ◽  
Mohammad R. Rezayat ◽  
Mohammad T. Jafari ◽  
Mehdi Bazarganipour ◽  
...  
Keyword(s):  
Room Temperature ◽  
Magnesium Aluminate ◽  
Synthesis And Characterization ◽  
Magnesium Aluminate Spinel ◽  
Adsorption Behaviour ◽  
Zeolitic Imidazolate Framework ◽  
Simple Method

New nanocomposite of zeolitic imidazolate framework-67@magnesium aluminate spinel (ZIF-67@MgAl2O4) has been fabricated by a simple method at room temperature with different weight ratios.

scholarly journals Optical glass-ceramics based on nanosized crystals of magnesium aluminate spinel doped with iron ions

2020 ◽  
Vol 1697 ◽  
pp. 012156
Author(s):  
V Bukina ◽  
O Dymshits ◽  
I Alekseeva ◽  
M Tsenter ◽  
S Zapalova ◽  
...  
Keyword(s):  
Optical Glass ◽  
Glass Ceramics ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Iron Ions ◽  
Nanosized Crystals

Transparency of zirconia and magnesium aluminate spinel ceramics manufactured by SPS technique

Ifost ◽  
2013 ◽  
Author(s):  
Khasanov Oleg ◽  
Dvilis Edgar ◽  
Kachaev Artem ◽  
Khasanov Alexey ◽  
Polisadova Elena
Keyword(s):  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel

Flash-sintering of magnesium aluminate spinel (MgAl2O4) ceramics

2016 ◽  
Vol 100 (2) ◽  
pp. 554-562 ◽  
Author(s):  
Hidehiro Yoshida ◽  
Papiya Biswas ◽  
Roy Johnson ◽  
Mantravadi Krishna Mohan
Keyword(s):  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Flash Sintering ◽  
Spinel Mgal2o4

Performance Studies on In Situ Spinel Solid Solution Bonded Periclase Refractories

2014 ◽  
Vol 633 ◽  
pp. 245-248
Author(s):  
Xin Lin ◽  
Yong Li ◽  
Yan Jing Li ◽  
Jun Jie Zhang ◽  
Chang He Gao ◽  
...  
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Performance Studies ◽  
Magnesium Aluminate ◽  
Spinel Solid Solution ◽  
Magnesium Aluminate Spinel ◽  
Crushing Strength ◽  
Cold Crushing Strength ◽  
Shock Resistance

Specimens were prepared using iron-rich magnesia (3~1 mm、≤1 mm) and high purity magnesia (≤0.088 mm) as the main starting materials, adding tabular alumina at different size (3~2、2~1、≤1 mm) and content:3%、6%、9%、12%、15% to discover the influence of tabular alumina on sample performance. Phase composition and microstructure were also analyzed. The results show that specimen with content of 6% of corundum possessed the best comprehensive performance:apparent porosity 17%, bulk density 2.95 g·cm-3, cold crushing strength 74 MPa, refractoriness under load 1700 °C, heat shock resistance of up to 18 times. The formations of magnesium aluminate spinel and hercynite solid solution were enhanced by Fe ion at high temperatures in the iron-rich magnesia-corundum system at the presence of iron oxides, which are able to largely dissolved in periclase.

Low cost foam-gelcasting preparation and characterization of porous magnesium aluminate spinel (MgAl2O4) ceramics

2016 ◽  
Vol 42 (16) ◽  
pp. 18215-18222 ◽  
Author(s):  
Xiangong Deng ◽  
Junkai Wang ◽  
Jianghao Liu ◽  
Haijun Zhang ◽  
Lei Han ◽  
...  
Keyword(s):  
Low Cost ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Porous Magnesium ◽  
Spinel Mgal2o4

Porous Wall Gas Lubricated Journal Bearings: Theoretical Investigation

1979 ◽  
Vol 101 (4) ◽  
pp. 458-465 ◽  
Author(s):  
E. P. Gargiulo
Keyword(s):  
Experimental Investigation ◽  
Dynamic Stiffness ◽  
Porous Wall ◽  
Companion Paper ◽  
Journal Bearings ◽  
Damping Properties ◽  
Governing Equations ◽  
Performance Curves ◽  
Unsteady Characteristics ◽  
Stiffness And Damping

A model has been developed to compute the dynamic stiffness and damping properties of externally pressurized, porous-wall, gas journal bearings which includes the effects of journal rotation and eccentricity. This paper presents the derivation of the governing equations and the perturbation analysis used to find the unsteady characteristics. Typical nondimensional performance curves are found and the influences of seven governing parameters are discussed. A companion paper describes an experimental investigation of porous journal bearings.

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