采用低温超音速等离子喷涂(LT-HVOF)在镍基高温合金基体上制备了Ni Co Cr Al YTa粘结层,使用大气等离子喷涂(APS)在粘结层上`制备了7wt%Y2O3-Zr O2(7YSZ)陶瓷层。基于动态试验即热震实验研究了粘结层的扩散氧化机制,探讨了陶瓷层的烧结...
详细信息
采用低温超音速等离子喷涂(LT-HVOF)在镍基高温合金基体上制备了Ni Co Cr Al YTa粘结层,使用大气等离子喷涂(APS)在粘结层上`制备了7wt%Y2O3-Zr O2(7YSZ)陶瓷层。基于动态试验即热震实验研究了粘结层的扩散氧化机制,探讨了陶瓷层的烧结及相变过程并观察了涂层的结构演变。实验结果表明:动态热循环下随着热震次数的增加,粘结层组元扩散氧化形成热生长氧化物(TGO)且厚度逐渐增加。此外,粘结层组元在温度梯度下沿陶瓷层内部裂纹向高温区扩散,最终在陶瓷层表面裂纹区域出现大量的金属氧化物,同时粘结层组元的扩散有助于陶瓷层的烧结,导致其显微硬度逐渐增大,而粘结层由于Kirkendall效应,其内部出现大量的孔洞导致其显微硬度逐渐降低。另外,陶瓷层在相变及热循环应力的作用下表面出现了大尺度的宏观裂纹。
A kind of W/DLC/W-S-C composite film was fabricated by magnetron sputtering *** of WSx content on the structure and the adhesion of the composite films were *** addition,tribological behavior of the composite films wa...
详细信息
A kind of W/DLC/W-S-C composite film was fabricated by magnetron sputtering *** of WSx content on the structure and the adhesion of the composite films were *** addition,tribological behavior of the composite films was studied in the conditions of the ambient air and N2 gas atmosphere by ball-on-disk *** results indicate that the composite films show dense and amorphous *** WCx and WSx compounds are found in amorphous diamond like carbon matrix in the top layers of W-S-C.A proper WSx content is beneficial for improving the adhesion of the composite *** air atmosphere,the composite films with high C content have better wear resistance and the friction coefficients range from 0.15 to *** N2 condition,high WSx content is benefit for the wear resistance and the friction coefficients of the composite films range from 0.03 to 0.1.
Al-doped zinc oxide(AZO) films were deposited on glass substrates by mid-frequency magnetron sputtering. The effects of substrate rotation speed and target-substrate distance on the electrical, optical properties an...
详细信息
Al-doped zinc oxide(AZO) films were deposited on glass substrates by mid-frequency magnetron sputtering. The effects of substrate rotation speed and target-substrate distance on the electrical, optical properties and microstructure and crystal structures of the resulting films were investigated by scanning electron microscopy(SEM), atomic force microscopy(AFM), X-ray diffraction(XRD), spectrophotometer and Hall-effect measurement system, respectively. XRD results show that all AZO films exhibit a strong preferred c-axis orientation. However, the crystallinity of films decreases with the increase of substrate rotation speed, accompanying with the unbalanced grains grows. For the films prepared at different target-substrate distances, the uniform microstructure and morphology are observed. The highest carrier concentration of 5.9×1020 cm-3 and Hall mobility of 13.1 cm^2/(V·s) are obtained at substrate rotation speed of 0 and target-substrate distance of 7 cm. The results indicate that the structure and performances of the AZO films are strongly affected by substrate rotation speed.
暂无评论