特征喷涂参数对等离子喷涂纳米 Al2 O3 -13%TiO2涂层微观结构及耐磨性能的影响

目的研究等离子喷涂纳米Al2O3-13%TiO2的特征喷涂参数(CPSP)对涂层微观结构及耐磨性能的影响,探索更合理的等离子喷涂工艺参数。方法采用等离子喷涂,在Q235钢表面制备过渡层为NiCrAl、陶瓷层为纳米Al2O3-13%TiO2的涂层系统。对涂层试样进行高温和常温磨损性能测试,并对比分析喷涂粉末、涂层的微观结构和相组成。结果纳米涂层为微观双模结构,由部分熔化区和完全熔化区组成,存在裂纹、孔隙等缺陷,其主要物相为α-Al2O3,γ-Al2O3和rutile-TiO2。纳米涂层磨损失效的主要原因是内部板条的分层剥落和涂层表面材料的塑性变形切削。结论随着CPSP的增大,纳米涂层的耐磨性能增强,且高温磨损性能较室温磨损性能为差。纳米Al2O3-13%TiO2涂层微观结构中部分熔化区结构和纳米晶粒的存在显著提高了涂层的耐磨性。

Influence of CPSP on Microstructure and Wear Property of Nanostructured Al2O3-13%TiO2 Coating Deposited by Plasma Spraying

ABSTRACT:Objective To study the influence of different critical plasma spray parameters ( CPSP) on the microstructure and the wear property of nanostructured Al2 O3-13%TiO2 coating deposited by plasma spraying so as to optimize the plasma spraying param-eters. Methods Nanostructured alumina-titania coatings with NiCrAl as the transition layer and Al2 O3-13%TiO2 as the ceramic lay-er on the surface of the Q235 steel were prepared by plasma spraying. The wear property of the coatings at room temperature and at high temperature was respectively tested, and phase constitutions and the microstructure of spraying powder and coating layer were respectively analyzed by XRD and SEM. Results The results showed that the nanostructured coating had a bio-model structure, consisting of PM region and FM region with defects such as crack and pore. The main phases were α-Al2 O3 , γ-Al2 O3 and rutile-TiO2 . Lamination and spallation of coating materials, and the plastic deformation of nanostructured coating materials were the main reasons for coating system failure during the sliding wear test. Conclusion With the ascending of CPSP, the wear property in-creased, and the wear property at room temperature was better than that at high temperature. The presence of PM region and nano-crystals in the nanostructured Al2 O3-13%TiO2 coating significantly increased the wear property.