Oxidation of Ni-based single crystal after grit-blasting during exposure at high temperature

The effect of grit-blasting on the oxidation of Ni-based single crystal at 1150 and 1250 °C was studied. The oxide scales formed on the samples with or without grit-blasting were characterized by SEM, XRD, EDS, and EPMA. The results indicate that grit-blasting introduces a plenty of oxide nodules with lamellar structure into the oxide scale of samples after oxidation. The oxide nodule is composed of external and internal part. The external part is multi-layered with outer Cr₂O₃ layer, inner Al₂O₃ layer and transitional layer. The internal part includes several alternative alloy layers lack of Al and Al₂O₃ layer. Hf and Ta segregate at the oxide/alloy and oxide/oxide interface in two parts. Two recrystallized grains are formed under the blasted alloy surface after grit-blasting and heat exposure. The formation of oxide nodules accelerates the development of equiaxed recrystallization. Grit-blasting introduces abundant paths of oxygen diffusion and residual stress into the alloy, promoting the formation of oxide nodules and recrystallization.     

阳极氧化法构建纳米结构制备铝超疏水表面

研究了喷砂和阳极氧化技术相结合,在铝合金表面构建合适的微米一纳米二级结构,并通过氟硅烷的修饰降低表面自由能,以制备铝基超疏水表面材料。研究表明：不同的电解液进行阳极氧化制得的样品氟化后具有不同的接触角。SEM分析可知,山峰山谷状的微米级结构和蜂窝状的纳米级结构形成的二级结构是提高疏水性能的关键。当接触水滴时,这种二级结构可以稳定地捕获空气,产生超疏水性。     

铝基超疏水表面的耐海水腐蚀性能研究

研究了喷砂和阳极氧化技术相结合,在铝合金表面构建合适的微米/纳米二级结构,并通过氟硅烷的修饰降低表面自由能,以制备铝基超疏水表面材料,并对表面的耐海水腐蚀性能进行了研究,研究表明,当采用100g/L硫酸、10g/L草酸、10g/L丙三醇作为电解液进行阳极氧化,孔洞孔径达200nm时,接触角达157°。模拟人工海水中的腐蚀实验,结果表明,超疏水表面材料的腐蚀速率比未经处理的空白试样缓慢一个数量级。     

Overblasting effects on surface properties of low-carbon steel

The influence of overblasting on surface properties of low-carbon steel was investigated. In detail, surface roughness, contact angle, Vickers-hardness, degree of surface contamination, and pull-off strength were evaluated. It was shown that overblasting had notable effects on the surface properties. Most importantly, the surface roughness was significantly reduced, and the microhardness of the substrate increased. Also, overblasting increased surface wettability. The influence on the pull-off strength of applied coating systems was only marginal.