论文标题
悬浮液中孔隙率的进化，通过中子散射和图像分析技术热喷涂YSZ热屏障涂层
Evolution of Porosity in Suspension Thermal Sprayed YSZ Thermal Barrier Coatings through Neutron Scattering and Image Analysis Techniques
论文作者
论文摘要
孔隙率是导热层涂层的关键参数，直接影响导热率和应变耐受性。悬浮液高速氧气燃料（SHVOF）热喷涂使使用亚微米颗粒作为原料，增加对孔隙率的控制并引入纳米孔；这些高尺度的孔隙度具有挑战性。中子散射代表了一种非破坏性技术，能够以小角度（SANS）和超小角度的中子散射（USANS）技术的结合，可以研究孔隙范围为1 nm至10 um的孔隙率。数字图像上的图像分析（IA）允许研究大小高于100 nm的孔隙率。在这项工作中，喷洒了两个Yttria稳定的氧化锆（ZRO2，ZRO2为8 wt。％Y2O3）悬浮液，并在1100、1200、1300和1400°C下进行了72小时的热处理。在Shvof 8ysz中，使用SANS和USANS和IA首次研究了孔径分布，总孔隙率和孔形态，以确定热处理的影响。进行了X射线衍射和微硬度测量，以研究相变，及其对涂层机械性能的影响。结果表明，在1100°C的热处理期间消除了纳米pores的大量存在；从切割间层间孔到球状孔的过渡以及微裂缝的出现，以及与从初始亚稳态四方到1200°C的相位转化到四方和立方相的相关的微水平的积累。相变在1400°C下完成，没有单斜相
Porosity is a key parameter on thermal barrier coatings, directly influencing thermal conductivity and strain tolerance. Suspension high velocity oxy-fuel (SHVOF) thermal spraying enables the use of sub-micron particles as feedstock, increasing control over porosity and introducing nano-sized pores; these fine-scale porosities being challenging to measure. Neutron scattering represents a non-destructive technique, capable of studying porosity with a pore size range of 1 nm to 10 um, thanks to the combination of small-angle (SANS) and ultra-small-angle neutron scattering (USANS) techniques. Image Analysis (IA) on digital images allows for the study of porosity with a size above ~100 nm. In this work, two yttria-stabilised zirconia (ZrO2 with 8 wt.% Y2O3) suspensions were sprayed and heat treated at 1100, 1200, 1300 and 1400 °C for 72 h. For the first time in SHVOF 8YSZ, pore size distribution, total porosity and pore morphology were studied using SANS & USANS and IA to determine the effects of heat treatment. X-ray diffraction and micro-hardness measurements were performed to study the phase transformation, and its effects on the mechanical properties of the coating. The results show an abundant presence of nano-pores in the as-sprayed coatings, which are eliminated during heat treatment at 1100 °C; a transition from inter-splat lamellar pores to globular pores and the appearance of micro-cracks along with the accumulation of micro-strains associated with the phase transformation from the initial metastable tetragonal into tetragonal and cubic phases at 1200 °C. The phase transformation was completed at 1400 °C, with no presence of monoclinic phase
