The Experimental Study Of Temperature Character Of Coating Elastic Modulus Based On Dynamic Method

The coating is widely used in industrial productions due to its anticorrosion and wear-resistant capability. The mechanical property of the coating has a strong impact on the safe operation of equipment, therefore, the mechanical property of the coating is very important and the Elastic modulus of the coating is essential for the analysis of stress and strain. In order to obtain its Elastic modulus accurately and comfortably, a testing device of the coating Elastic modulus is developed in this thesis by dynamic method which can work at different temperatures.Conventional testing methods of Elastic modulus of the coating are analyzed and then a method of hanging coupling resonance of the coating Elastic modulus is proposed in this thesis.The relationship between the Elastic modulus of the composite coating specimen, the base, the coating and the resonance frequency is derived.The testing system platform of the dynamic method is set up, which includes choice of the transducer, hanging wire and furnace, design and fabrication of testing platform, and composite specimen with coating.In order to obtain the resonant frequency of the specimen, and then obtain the Elastic modulus, the testing system is established which is divided into two parts:excitation and incentive pick-up. The pulse as excitation signal of the system is achieved via a VB software programming, UA355 D/A, amplifier. The resonant frequency of the specimen is acquired via the design of pick-up signal processing circuit, DAQ UA301, signal analysis based on LabVIEW software.Taking typical samples with a rectangular section of high temperature alloy and aplasma spraying ceramic coating of Al2O3, the resonant frequency of composite coating specimen is measured by the testing system platform. With the help of the theoretical model, the coating's Elastic modulus is calculated with the VB software.