Study On The Preparation And Properties Of Piezoelectric Ceramic Coatings Based On Thermal Spraytechnology

Surface engineering is a technology in improving the surface properties of parts, inwhich the thermal spraying techniques are the key technologies in the preparation of thecoatings, however the traditional fatigue wear of coatings are failure to judge mainly relyon local fracture after coatings under high-speed operation of mechanical vibration signalsgenerated by friction noise, it is a kind of judge that after coatings failure, however, thecoatings service process, the dynamic damage cannot real-time perception, fabrication ofpiezoelectric coatings by thermal spraying coatings on serving the damage in the process ofreal-time monitoring is an important research direction.This paper mainly studied the PZT piezoelectric coatings prepared by supersonicplasma spraying. Firstly, the PZT powders were prepared by the method of solid sintering,and the phase composition, microstructure, etc of the powders were analysis, and thesintering process were determined. The PZT powders were sprayed, and the orthogonaloptimization experiments were carried out on45#steel. Respectively, the scanning electronmicroscopy, X-ray diffraction, micro-hardness tester and other detection methods wereused to detect the interface morphology, relative structure, micro-mechanical properties ofPZT coatings, in addition, the silver electrode were prepared on the surface of coatings, theimpedance analyzer and piezoelectric constant tester were used to test the electricalproperties of the PZT coatings, and the polarization process of the PZT coatings weredetermined.The result shows:(1)The sintering process of the PZT powders is incubated1.5hoursat650℃and heating to heat850℃2hours, and finally maintain at1200℃4hours whichcould obtain a preferably powder phase structure;(2)The supersonic plasma sprayingprocess parameters on the performance of PZT coatings integrated primary and secondaryorder: Ar gas flow rate>spray distance>spray current>spray voltage, and the best sprayingprocess is that the spray current400A, spray voltage120V, argon gas flow3.2m3/h and aspray distance100mm;(3)The PZT coatings which are prepared by the best sprayingparameters have a more smooth surface morphology, bond strength of41.3M Pa, compactstructure and a porosity of1.62%, the average micro-hardness is568.9HV, the averagenano-indentation hardness of7.122Gpa, the average modulus of123.051Gpa;(4)Thedielectric constant of PZT coatings is determined and It is stability. The Curie temperatureof PZT coatings is about370℃, the polarization voltage is4KV/mm, the polarizationtemperature is120℃, the polarization time is25min, and the d33of PZT coatings up to72pC/N. The piezoelectric ceramic coatings prepared by spraying is feasible, using piezoelectric coatings for real-time monitoring of service parts in the process of runningstate has a very bright future, but further studies are needed.