The Influence Of Nano-CeO₂,Al₂O₃,TiO₂ Powders On Wear Resistance Of Al₂O₃/TiO₂ Coating

The high temperature abrasion of utility boiler tubes(water wall,super heater,reheater,economizer tubes)is recognized as being one main cause of utility boiler tube failures.Not only the security to the power plant is threatened,but also the provisional time to examine and repair of power plant will be increased because of the explosion and the leakage of the boiler tubes.One economical and possible way to attack this problem is the use of thermal spraying on boiler tubes which can control the high temperature abrasion effectively.The Al2O3 spraying that adding right amounts of nano-Al2O3 powder,nano-TiO2 powder,nano-CeO2 powder,contents of which was designed by orthogonal was prepared by subsonic speed flame spraying based on analyzing the high temperature abrasion of utility boiler tubes.The microstructure and the phase of the Al2O3 spraying were studied by SEM,optical microscopy and X-Ray.The wear resistance was tested by frictional wear tester;the anchoring strength of the spraying was tested by tensile tester.The influence of nano-CeO2 on the microstructure and the wear resistance of Al2O3 spraying were studied in this text,and also the functional mechanism of the nano-Al2O3 powder,nano-TiO2 powder and the nano-CeO2 powder in Al2O3 ceramic spraying was analyzed.The results show:the structure of coating was refined,the distribute of orgination was improved,the porosity was decreased,the wear resistance and the anchoring strength of the spraying were improved when adding right amounts of nano-CeO2,nano Al2O3,nano-TiO2 powder.The combination that the wear resistance and the anchoring strength of the spraying were best was A1B1C3D2 in this paper.It was 4%nano- Al2O3+4%nano-TiO2+5%nano-CeO2 +2%nano-Ni+54%micro-Al2O3+13%micro-TiO2+8%micro-Cr3C2+8%micro-Ni+2%micro-Cr.The function mechanism of nano-CeO2,nano-Al2O3 and nano-TiO2 powder in Al2O3 spraying was summaried.Theoretical foundation of Application of nano-CeO2,nano-Al2O3 powdr and nano-TiO2 powder in spraying was offerd.The new route that the application of nano-CeO2 powder,nano-Al2O3 powder and nano-TiO2 powdr in thermal spraying was opend up.