Method for measuring interface bonding strength of thermal barrier coating layer

Abstract

The invention relates to the measurement field of mechanical properties of materials and particularly relates to a method for measuring the interface bonding strength of a thermal barrier coating layer. The method comprises the following steps: (1) acquisition of stress-strain data: firstly preparing a measuring test piece, and acquiring and recording a load-displacement curve by virtue of a three-point bending method so as to acquire the stress-strain data; (2) calculation of crack length: representing the deformation of the measuring test piece by virtue of a digital image relevant method, and combining with the displacement of an open angle to determine a crack tip position, so as to calculate the crack length; and (3) calculation of energy release rate: after the stress-strain data and the crack length are acquired, calculating the energy release rate by virtue of a flexibility method. According to the method provided by the invention, by utilizing the characteristic that the breakable thermal barrier coating layer and a hard alloy matrix are different when being deformed by virtue of an external force, the external force is applied to an alloy basement by virtue of an improved three-point bending method, and the interface bonding strength of the thermal barrier coating layer with a deformed interface is represented by virtue of the digital image relevant method.

Description

technical field [0001] The invention relates to the technical field of measuring mechanical properties of materials, in particular to a method for measuring the interface bonding strength of a thermal barrier coating. Background technique [0002] Thermal barrier coating refers to a "laminated" system in which a metal buffer layer or a metal bonding layer and a ceramic layer with good heat resistance and heat insulation are combined with the metal surface to function as heat insulation protection. That is, metal-ceramic composite coating system. Thermal barrier coatings mainly use the characteristics of low thermal conductivity, high melting point, corrosion resistance and wear resistance of ceramic materials to reduce the surface temperature of blades and protect blades, thereby improving the efficiency of gas turbines. The current study shows that the ceramic layer can produce a temperature drop of up to 300°C. The classic thermal barrier coating structure includes an ul...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a method that utilizes the inconsistency between the brittle thermal barrier coating and the cemented carbide substrate when it is deformed by an external force, and applies an external force on the alloy substrate through an improved three-point bending method until the layered structure interface The method of measuring the interfacial bond strength of thermal barrier coatings that is destroyed and characterized by the digital image correlation method can solve the shortcomings of the single interface bond strength measurement method in the prior art

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