Test sample and test method for bonding strength of ceramic coating, and preparation method of test sample

Abstract

The invention discloses a test sample and a test method for bonding strength of ceramic coating, and a preparation method of the test sample. Specifically, the test sample comprises a substrate, a ceramic layer, a rigid beam and a support block, wherein the ceramic layer is disposed on the substrate; the support block and the ceramic layer are both adhered to the rigid beam and located on the sameside of the rigid beam with a space there-between, and the length of the support block is smaller than that of the ceramic layer in the first direction. Such structural arrangement, since delamination cracks are initiated at the interface end of one side, effectively avoids the problem of crack propagation instability in the prior art, and obtains the fracture characteristics of the ceramic layerby the displacement-load curve measurement of the loading point, without real-time measurement of the extended length of the coating interface cracks, which makes the test method easier and faster.

Description

technical field [0001] The invention relates to the technical field of testing and evaluating the mechanical properties of materials, in particular to a test sample, a preparation method and a testing method for the bonding strength of a ceramic coating. Background technique [0002] With the development of large-scale power equipment such as modern gas turbines and aero engines, the working environment temperature of key components is getting higher and higher, which has far exceeded the melting point of current high-temperature resistant alloy materials. In order to improve the high temperature resistance and service life of the hot end parts of these power equipment, thermal spraying or physical vapor deposition of ceramic coating materials with good high temperature resistance and heat insulation performance on the surface of metal components, such as yttrium oxide reinforced zirconia (YSZ), etc., And through the transition and bonding of the transition layer, the bondin...

AI Technical Summary

Problems solved by technology

The tensile method, shear method, scratch method and bubbling method have difficulties in making samples, or need to measure the length of crack propagation in real time and in situ, which is extremely difficult to achieve for tiny materials

In comparison, the bending specimen of the "sandwich" sandwich structure has the advantages of simple specimen geometry and convenient testing technology. Charalambides et al. applied such as figure 1 The four-point bending method shown is used to test and theoretically estimate the fracture toughness of the metal / ceramic interface, but this sample requires two strictly symmetrical fatigue pre-cracks, and the difficulty is how to maintain the symmetry of the pre-cracks during the experiment , balanced expansion, slight vibration or unbalanced loading during the experimental loading process will lead to crack growth instability, which will bring great difficulties and errors to the testing and characterization of the bonding strength of ceramic coatings

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