Measurement of Young’s modulus of oxides at high temperature related to the oxidation study

Abstract

a-Al 2 O 3 , Cr 2 O 3 , and a-Fe 2 O 3 specimens were prepared by a sintering process. A 400 -1000-Hz sine wave was applied to the specimen at 290 -1273 K. The applied and respond waves were monitored by using force and acceleration sensors. The intensity ratio and phase shift between the applied and respond waves were analysed, and the anti-resonance frequency was obtained. Young's moduli of a-Al 2 O 3 , Cr 2 O 3 , and a-Fe 2 O 3 are estimated to be 386, 286, and 220 GPa at 298 K, respectively. The temperature dependence values of these oxides are estimated to be 54.3, 46.9, and 42.0 MPa K À 1 , respectively. The temperature dependence of Young's modulus can be classified on the basis of the crystal structure of solids. The estimation of Young's modulus at 1273 K is possible with an error range of 10 -30 GPa for a crystalline solid if the crystal structure of the solid is known. It is found that the temperature dependence of Young's modulus depends on the density of the oxides, and an experiment in which well-characterized crystalline solids are used must be conducted to minimize the error range.

The Effect of Deposition Parameters on the Structure and Mechanical Properties of Chromium Oxide Coatings Deposited by Reactive Magnetron Sputtering

“…When the deposition pressure was in the range of 1-0.29 Pa, the chromium oxide coatings had an average hardness and Young's modulus value of about 5 and 80 GPa, respectively. This result is consistent with Figure 6 in Kao's [4] research, in which chromium oxide coatings showed a low hardness value of 8 GPa when deposited at a process pressure between 0.5-2.5 Pa. Decreasing the operation pressure to 0.16 Pa, the hardness and Young's modulus of the coatings increased significantly and reached an average hardness and Young's modulus value of about 25 and 289 GPa, respectively, which is near the bulk Cr2O3 values reported in previous literature [1][2][3][4]34]. According to structural analysis results, it can be inferred that the low hardness of the chromium oxide coatings deposited at higher pressures was due to the formation of mixed chromium oxide phases.…”

Nanoindentation of Chromium Oxide Possessing Superior Hardness among Atomic-Layer-Deposited Oxides

“…The previous reports have indicated the Cr 2 O 3 thin films possess a high hardness of over 20 GPa [ 10 , 14 , 15 , 30 , 31 , 32 ]. In some conditions the processes produced chromia with lower hardness, even down to an 8–10 GPa level [ 14 ].…”

A New Al2O3‐Protected EB‐PVD TBC with Superior CMAS Resistance

“…The introduction of a built‐in α‐Al 2 O 3 protection network is inevitable to raise the elastic modulus of TBCs structure (Figure 6 ) attributed to coating porosity reduction and introduction of stiffer Al 2 O 3 ( E Al2O3 ≈386 GPa; [ 48 ] E YSZ ≈205 GPa). This work investigated the effect of injected Al 2 O 3 on the Young's modulus of TBCs, and the effect of drip coating times on the Young's modulus of TBCs.…”