Fracture characteristics of freestanding 8wt% Y2O3–ZrO2 coatings by single edge notched beam and Vickers indentation tests

Abstract

a b s t r a c tThe freestanding 8 wt% Y 2 O 3 -ZrO 2 (8YSZ) samples prepared by an air plasma sprayed technique were measured by single edge notched bending tests. The strain evolution and cracking near a pre-existed notch region were in-situ monitored by digital image correlation. With the help of digital image data, the critical bending loads of these notched freestanding 8YSZ samples can be accurately determined. The fracture toughness and micro-hardness of freestanding 8YSZ samples were tested by Vickers indentations. The normalized fracture toughness calculated according to the Weibull statistics is in agreement with the testing and available data. These results are instructive in predicting the lifetime and durability of thermal barrier coatings with irregular geometric structures.

High temperature digital image correlation evaluation of in-situ failure mechanism: An experimental framework with application to C/SiC composites

“…2). The similar work was shown in our previous results [18]. Finally, the specimens were cleaned by an ultrasonic oscillator with distilled water, and then completely dried before bending tests.…”

“…The sampling rate of the camera was set as one image per second in this work. The detailed information was described in our previous works [16,[18][19][20][21][22]. In order to observe the crack nucleation and propagation patterns clearer, we added a telephoto zoom Nikon lens and a 490 nm optical band pass filter in front of the camera (see Fig.…”

Study of mechanical properties and cracking extension resistance behavior of C/SiC composites by single edge notched beam and digital image correlation techniques

“…1). The similar work was shown in our previous results [33]. Finally, the specimens were cleaned by an ultrasonic oscillator with distilled water, and then completely dried before bending tests.…”

“…The sampling rate of the camera was set as one image per second. The detailed information was described in our previous works [27,[33][34][35][36]. In order to observe the crack nucleation and propagation patterns clearer，a telephoto lens with an optical enlargement factor of 200X was equipped in front of the camera, as shown in Fig.…”

“…7 The experimental data was recorded by computers for estimating the material properties of C/SiC specimens. For SENB tests, fracture strength, b  , and fracture toughness, IC K , can be obtained by the following formulas [33,41], respectively,…”