To improve the oxidation resistance and corrosion resistance of Zr-4 alloy, titanium nitride(TiN) coatings were prepared on the Zr-4 alloy with a TiN ceramic target with different ratios of N_2. Microstructure and hig...To improve the oxidation resistance and corrosion resistance of Zr-4 alloy, titanium nitride(TiN) coatings were prepared on the Zr-4 alloy with a TiN ceramic target with different ratios of N_2. Microstructure and high-temperature properties of the TiN coated samples were studied by scanning electron microscopy(SEM), energy dispersive spectrometer(EDS), X-ray diffraction meter(XRD), X-ray photoelectron spectroscopy(XPS), heat treatment furnace and autoclaves, respectively. The x value of the TiN coatings(TiN_x) ranges from 0.96 to 1.33. After the introduction of N_2, TiN coating exhibits a weak(200) plane and a preferred(111) orientation. The coating prepared with an N_2 flow ratio of 15% shows an optimal oxidation resistance in the atmospheric environment at 800 °C. In either 1 200 °C steam environment for one hour, or deionized water at 360 °C and a pressure of 18.6 Mpa for 16 d, the opitimized TiN coated samples have no delamination or spallation; and the gains in the masses of samples are much smaller than Zr-4 alloy. These results demonstrate the effectiveness of the optimized TiN coating as the protective coating on the Zr-4 alloy under extreme conditons.展开更多
实时预测民航发动机滑油量对保障飞行安全具有重要意义。针对滑油量受发动机多个工作状态的多个参数影响,具有影响参数多,提取方法不确定等问题,提出了一种基于邻域粗糙集(neighborhood rough set,NRS)和灰狼优化(grey wolf optimizer,G...实时预测民航发动机滑油量对保障飞行安全具有重要意义。针对滑油量受发动机多个工作状态的多个参数影响,具有影响参数多,提取方法不确定等问题,提出了一种基于邻域粗糙集(neighborhood rough set,NRS)和灰狼优化(grey wolf optimizer,GWO)-Elman相结合的方法预测滑油量。首先通过邻域粗糙集提取对滑油量重要度高的发动机工作阶段,将提取后的工作阶段有关参数作为特征向量输入到灰狼优化-Elman的网络模型中,灰狼算法通过计算和比较个体的适应度来优化Elman网络中的权值和阈值,保证Elman网络中的权值和阈值达到全局最优。预测结果表明,精度达到98.44%,满足工程应用的精度要求。研究结果为及时监测民航发动机滑油系统的健康状况提供理论依据。展开更多
基金Funded by the National Science and Technology Major Project of the Ministry of Science and Technology of China(2015ZX06004001-002)the Postgraduate Research and Innovation Project of the University of South China(2017XCX11)
文摘To improve the oxidation resistance and corrosion resistance of Zr-4 alloy, titanium nitride(TiN) coatings were prepared on the Zr-4 alloy with a TiN ceramic target with different ratios of N_2. Microstructure and high-temperature properties of the TiN coated samples were studied by scanning electron microscopy(SEM), energy dispersive spectrometer(EDS), X-ray diffraction meter(XRD), X-ray photoelectron spectroscopy(XPS), heat treatment furnace and autoclaves, respectively. The x value of the TiN coatings(TiN_x) ranges from 0.96 to 1.33. After the introduction of N_2, TiN coating exhibits a weak(200) plane and a preferred(111) orientation. The coating prepared with an N_2 flow ratio of 15% shows an optimal oxidation resistance in the atmospheric environment at 800 °C. In either 1 200 °C steam environment for one hour, or deionized water at 360 °C and a pressure of 18.6 Mpa for 16 d, the opitimized TiN coated samples have no delamination or spallation; and the gains in the masses of samples are much smaller than Zr-4 alloy. These results demonstrate the effectiveness of the optimized TiN coating as the protective coating on the Zr-4 alloy under extreme conditons.
文摘实时预测民航发动机滑油量对保障飞行安全具有重要意义。针对滑油量受发动机多个工作状态的多个参数影响,具有影响参数多,提取方法不确定等问题,提出了一种基于邻域粗糙集(neighborhood rough set,NRS)和灰狼优化(grey wolf optimizer,GWO)-Elman相结合的方法预测滑油量。首先通过邻域粗糙集提取对滑油量重要度高的发动机工作阶段,将提取后的工作阶段有关参数作为特征向量输入到灰狼优化-Elman的网络模型中,灰狼算法通过计算和比较个体的适应度来优化Elman网络中的权值和阈值,保证Elman网络中的权值和阈值达到全局最优。预测结果表明,精度达到98.44%,满足工程应用的精度要求。研究结果为及时监测民航发动机滑油系统的健康状况提供理论依据。
