热处理对EB-PVD制备的TiAl/Nb复合材料微观组织的影响

对利用EB-PVD技术制备的TiAl/Nb微层板进行了热处理,分析了沉积态材料与热处理态材料的组织结构和物相的变化。热处理TiAl/Nb中态富Ti的TiAl层中成分沿沉积方向呈有规律的梯度变化但未形成周期,界面处的反应扩散区由B2相组成;TiAl层、扩散区和Nb层的显微组织形貌依次为含月牙形亚晶的柱状晶、细小等轴晶和粗大等轴晶;经1000℃/16h的真空退火处理后,Nb层和扩散区会因完全扩散而消失。     

Oxidation and lifetime of PYSZ and CeSZ coated Ni-base substrates with MCrAlY bond layers

Abstract

IN100 blades and CMSX-4 samples with NiCoCrAlY bond coats manufactured via LPPS and EB-PVD were cyclically tested in a burner rig at 1120°C and a furnace at 1100°C. Two different TBC chemistries were deposited by EB-PVD techniques: PYSZ and CeSZ. In all cases the performance of the CeSZ coated variances was superior to the PYSZ coated counterparts. TGO growth kinetics were slightly slower for the CeSZ coated samples. The benefits in lifetime are mainly attributed to the mixed zone oxides that tolerate spinel phase formation due to their ability to “wet” each other. Pore formation in the mixed zone is hereby suppressed favoring crack blunting mechanisms.     

熔盐环境下热障涂层的等温热腐蚀行为研究

采用电子束物理气相沉积（EB-PVD）在镍基高温合金表面制备了YSZ/NiCoCrAlY双层结构热障涂层,研究了其在熔盐环境下的等温热腐蚀行为。结果表明,涂层在加热过程中发生相变引起体积收缩,导致涂层内部产生微裂纹。熔盐填充涂层内微裂纹和柱状晶间隙,降低了涂层的应变容限,引起涂层内应力升高。同时,熔盐促使热生长氧化层（TGO）碱性溶解,产生疏松多孔的氧化物层,导致TGO层加速增厚。在热应力作用下,疏松层氧化物破碎,最终导致涂层剥落。     

基板温度对EB-PVD ZrO2涂层微观组织及残余应力的影响

采用电子束物理气相沉积(EB-PVD)技术在不锈钢基板上沉积ZrO2涂层.研究基板温度对涂层微观组织和残余应力的影响.结果表明:沉积的涂层均为t-ZrO2结构,涂层表面平整致密;随着基板温度的升高,涂层表面颗粒逐渐长大,表面粗糙度增大;涂层残余应力也随着基板温度的升高而增加,当基板温度为1000 ℃时,涂层残余应力的增量最大,ZrO2涂层的残余应力主要是由于涂层与基板热膨胀系数差别而产生的热应力引起.     

EB-PVD制备钛合金薄板渗铝相结构转变研究

对电子束物理气相沉积（EB-PVD）技术制备的钛合金薄板进行粉末包埋法渗铝，研究不同温度渗铝后的相结构转变规律。结果表明：制备态合金薄板相结构为Ti和Ti3Al，材料组织致密均匀，X射线衍射峰发生宽化，具有不对称性。在较低温度（600℃和620℃）渗铝后薄板两边的相结构变为Al3Ti相，但薄板的中心部位仍然为制备态的Ti3Al相，两边的Al3Ti组织和中心部位的Ti3Al组织都很均匀致密。在两相之间，存在清晰、平整的界面。在较高温度（700℃）渗铝后薄板的相结构为A13Ti，此时整个板材都被渗穿，组织均匀致密，并在局部小区域内出现铝元素的富集。     

EB-PVD热障涂层热循环性能评价方法研究

制备8批次EB-PVD双层结构热障涂层试样,采用循环加热快速冷却实验装置模拟热障涂层服役环境,开展了热障涂层试样在不同热循环保温时间条件下的热循环性能评价实验,采用指数下降的数学模型对热循环实验数据进行拟合分析,获得了表征热障涂层试样静态氧化性能和热疲劳性能的物理量.结果表明,在本实验工艺条件下制备的不同批次热障涂层试样的静态氧化性能和热疲劳性能具有不同的匹配关系,热障涂层试样静态氧化性能总体估计值为(677±194)h,热疲劳性能总体估计值为(6789±1818)次.     

Failure mechanism of a (Ni,Pt)Al/EB-PVD 8YSZ deposited on substrate with different curvature signs in thermal shock test

A thermal shock test was conducted on an 8 wt% Y₂O₃ stabilized ZrO₂ electron beam-physical vapor deposited (EB-PVD 8YSZ) thermal barrier coating with a (Ni, Pt)Al bond coating on the substrate with different curvature signs. The microstructural evolution and durability have been characterized. The microstructure of the top ceramic layer is strongly dependent on the substrate geometry. The results of the thermal shock test indicated that the sample with a positive curvature exhibits mixed mode spalling by the linking of cracks at TBC/TGO interface and TGO/BC interface. Spallation occurs primarily at the TGO/BC interface and inside the bond coats near to the surface of bond coats in planar samples. The spalling occurs principally at the TGO/BC interface in specimens with a negative curvature. The failure mechanism is elucidated integrate with stress analysis.     

EB-PVD梯度热障涂层的制备及其热疲劳性能

采用ＥＢ－ＰＶＤ的方法,连续蒸发按一一分比混合的Ａｌ＋Ａ１２Ｏ３＋ＺｒＯ２混合源,在Ｎｉ基高温合金基体上制备了一种新型结构的热障涂层,ＳＥＭ和ＥＤＳ的观察、分析表明,这作层实现了由金属粘结层向陶资顶层的微观结构的梯度过渡和化学成分的连续变化。涂层的基本结构为ＮｉＣｏＣｒＡ１Ｙ／Ｎｉ３Ａｌ＋Ａ１２Ｏ３／Ａ１２Ｏ３ＺｒＯ２／ＺｒＯ２。这北度热障涂层在１０５０℃的抗高温氧化性能优于传统的二层结构的热障涂     

热障陶瓷涂层的发展现状和前景

从热障涂层的材料、制备手段、涂层制备工艺 等角度综述了热障陶瓷涂层的发展现状,讨论了制备工艺、涂层结构对涂层性能的影响,最后指出了涂层的技术发展趋势和应用前景.