Substrate Constraint Induced Enhanced Anisotropic Healing Kinetics of 2D Pores in Plasma-Sprayed The

来源 :第十一届全国表面工程大会暨第八届全国青年表面工程学术会议 | 被引量 : 0次 | 上传用户:wylalone
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
  2D pores, including inter-splat pores and intra-splat cracks, play a dominant role on the thermal barrier effect and strain tolerance of plasma-sprayed thermal barrier coatings. Consequently, the healing of 2D pores during thermal exposure is mainly responsible for the sintering induced performance degradation. The differences in morphology, size and grain orientation between inter-splat pores and intra-splat cracks contribute to anisotropic healing kinetics of these 2D pores in commonly-used free-standing yttria-stabilized zirconia coatings (YSZ). This study examined the healing evolution of 2D pores in YSZ coatings attached to substrate. Results show that the anisotropic healing kinetics of 2D pores is distinctly enhanced on the coatings attached to substrate. At initial thermal exposure duration, the constraint on sintering-induced contraction of coatings and the positive mismatch of thermal expansion coefficients result in global tensile effect and compressed effect in in-plane direction and out-plane direction, respectively. Consequently, the inter-splat pores become narrowed, while the intra-splat cracks are widened. The stressed coatings lead to a much more severe healing of inter-splat pores than do intra-splat cracks. The properties evolution (like elastic modulus and ionic conductivity) also presents enhanced anisotropic evolution trends with respect to the free-standing coating. In other words, a faster and higher increment in out-plane direction occurs during thermal exposure. At an extended thermal exposure duration, the stiffened coating attributed by enhanced bonding ratio leads to some larger cracks in coating surface to release the constrained stress. Consequently, the healing of the micro intrasplat cracks near the large cracks was significantly enhanced.
其他文献
In this work, to investigate the effect of colloidal particle on formation and properties of micro-arc oxidation coating on 6061 alumin m alloy, we adopted Na2SiO3+NaOH+Na2EDTA (refer to A) and Na2SiO
按铬及钼原子比1:1比例将二硼化铬及二硫化钼均匀混合的粉末作靶体.脉冲磁控溅射法在314不锈钢及硅基体上同时制备混合成份涂层.分别用扫描电子显微镜、X射线衍射分析涂层形貌及相结构,表面形貌轮廓仪测量涂层厚,纳米压痕仪检测涂层纳米硬,摩擦磨损实验机测量涂层摩擦系数.结果 表明,涂层致密、无缺陷,其晶体择优取向分别为硼化铬的(111)及二硫化钼的(200).随脉冲频率增高,涂层的沉积速率降低,与有效沉
生物医用材料表面性能包括表面形貌及化学组成,对诱导骨组织形成并形成骨整合具有重要作用.细胞行为对基底表面形貌和组成的依赖性决定了设计不同功能表面的重要性.微纳结构材料表面具有利于细胞粘附及部分细胞增殖或分化等优势;人体微量元素硒具有抗肿瘤、抗衰老、调高人体免疫力等作用;羟基磷灰石(HA)作为生物体硬组织的主要成分,因其良好的生物相容性及骨诱导性被广泛应用于生物医学领域.因此,在本课题使用水热合成法
In order to improve the tribological properties of Ni-based composite coatings, the composite coatings were prepared by atmospheric plasma spraying and heat treated at at 400 oC,500 oC and 600 oC, res
烧结聚晶金刚石(Polycrystalline Diamond,PCD)是由经过筛选的人造金刚石微晶体和粘结剂Co在高温(1400℃)、高压(6 GPa)下烧结而成的复合材料,PCD具有超高的硬度、良好的冲击韧性和优异的耐磨性,被广泛应用于切削刀具和地质钻具.钻具加工及其应用过程中,PCD表面会产生大量的切削热,且常服役于由水、钻井液、钻井泥浆组成的复杂流体润滑系统,湿热复合作用对聚晶金刚石/岩石
Nitriding and Carburizing methods are widely used to improve the performance of titanium alloy in terms of hardness and wear resistance. However, titanium alloy possesses low thickness of cementation
Micro-arc Oxidation (MAO) is a new technology for non-ferrous metal surface treatment through growth ceramic layer on the original surface. This article uesed the pulse power supply with a discharge c
WC硬质合金由于优异的性能已广泛应用于现代工业,然而在环境空气和水环境中WC硬质合金呈现出严重的磨损效果。为了改善WC硬质合金的摩擦学性能并拓展其应用领域,采用磁控溅射技术选取Cr/Ce复合靶并激发CH4在YG8硬质合金(WC)表面沉积(Cr,Ce)/a-C:H薄膜。用原子力显微镜(AFM)、X射线衍射仪(XRD)、Raman光谱、场发射扫描电子显微镜(FESEM)、透射电镜(HRTEM)、XPS
Tungsten trioxide (WO3) is an indirect bandgap semiconductor and has been identified as one of the most promising inorganic working electrode materials for electrochromic, electrocatalytic, photocatal
Surface texturing is the process of applying a specific pattern of roughness onto a surface in order to improve its tribological properties. In this paper, the micro/nano texture was fabricated on the