Method for testing nano-indentation of coating property

Abstract

The invention discloses a method for testing a nano-indentation of a coating property. The method comprises the following specific steps of fixing a sample on a sample holder of a nano-indentation test system; regulating the temperature of the sample and a pressure head by using a temperature module, so that the sample and the pressure head are kept at a target temperature; applying and unloadinga load on the coating surface according to the set, and synchronously recording the depth of the indentation to obtain a load-depth curve; and calculating mechanical parameters of the coating based onthe load-depth curve. The temperature module enables the pressure head and the sample to reach the target temperature and maintain the target temperature and then an indentation test is carried out,so that the temperature of the sample, the pressure head and a contact point during the measurement process is ensured to be not changed, the load-depth curve of various temperature conditions can beobtained, and mechanical parameters of the coating at various temperatures can be calculated conveniently. Meanwhile, the problems of temperature gradient and thermal stress formed between the sampleand the pressure head are avoided, and the precision of the load-depth curve is effectively guaranteed.

Description

technical field [0001] The invention relates to the technical field of material mechanical performance testing and evaluation, in particular to a nano-indentation testing method for coating performance. Background technique [0002] In order to improve the thermal efficiency and power performance of large power equipment such as modern gas turbines and aero engines, a large number of thermal protective ceramic coating materials are used on the hot end parts. In the actual service process of thermal barrier coatings, they work in a periodically changing high-temperature rotating environment for a long time. The materials of each layer are not only affected by stress forms such as stretching, bending and shearing, but also by thermal stress loads, that is, thermal-force Combined load environment. Due to the heterogeneity of the composition and structure of the thermal barrier coating material system, there is a mismatch between the materials of each layer and the substrate in...

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Problems solved by technology

At the same time, the duty cycle will cause drastic temperature changes in the coating, interfacial oxidation and continuous accumulation of residual stress, which gradually lead to delamination or peeling of the thermal barrier coating from the substrate

[0003] At present, the mechanical properties of most thermal barrier coatings are still carried out at room temperature, which is quite different from the actual application temperature environment. It is impossible to accurately obtain the actual mechanical properties of thermal barrier coatings in working conditions, which is not conducive to thermal barrier coatings. layer reliability and service life for accurate predictions

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