表面纹理和表面膜对Ti6Al4V合金空蚀特性的影响

为研究表面纹理和表面膜对材料抗空蚀特性的影响,采用激光表面改性的方法对Ti6Al4V合金进行纹理加工,在纹理加工试样上采用自组装技术制备自组装分子膜。采用接触角测量表征试样的表面特性,通过对试样的抗空蚀特性进行测试和对试样空蚀前后的表面形貌进行观测,分析试样的空蚀发生机制。结果表明,Ti6Al4V试样上激光加工表面纹理可显著提高其抗空蚀能力,纹理加工试样上制备自组装分子膜,由于具有疏水特性可以进一步改善试样的抗空蚀能力;网格纹理试样的抗空蚀能力由于表面硬度高、硬度梯度大及突起高硬度点分布均匀而强于直线纹理试样;沉积薄膜纹理试样的抗空蚀能力随着间距的增大而增大,未沉积薄膜试样的抗空蚀能力随着间距的增大而减小。

Influence of Surface Texture and Surface Film on Cavitation Erosion Characteristics of Ti6Al4V Alloy

Surface texture manufacturing to Ti6Al4V alloy by a laser surface modification method and self-assembled monolayers (SAMs) prepared on the texturing surface by a self-assembled method were conducted in order to study the effect of surface texture and surface film on the characteristics of cavitation erosion resistance of materials. The surface properties of the specimens were characterized by measurement of contact angles. Cavitation erosion mechanism of the specimens was analyzed by measurement of cavitation erosion characteristics and topography observation before and after cavitation erosion occurrence. The results indicate that cavitation erosion resistance of Ti6Al4V specimens are significantly enhanced by laser texture manufacturing. The cavitation erosion resistance is further improved by self-assembled monolayers prepared on texturing surface because of the hydrophobicity. The cavitation erosion resistance of specimens with grid texture is bigger than that of specimens with line texture because the former possesses higher hardness, higher hardness gradient and even protrudent hard point distribution. The cavitation erosion resistance of specimens with FOTS SAMs for both grid texture and line texture increases with space increasing. The cavitation erosion resistance of specimens without FOTS SAMs for both two textures decreases with space increasing