Oxidation and fatigue behaviour of γ-TiAl coated with HIPIMS CrAlYN/CrN nanoscale multilayer coatings and EB-PVD thermal barrier coatings
Oxidation and fatigue behaviour of γ-TiAl coated with HIPIMS CrAlYN/CrN nanoscale multilayer coatings and EB-PVD thermal barrier coatings
复制标题
HIPIMS CrAlYN/CrN纳米多层涂层和EB-PVD热障涂层γ-TiAl的氧化和疲劳行为
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
A. Ehiasarian
中科院分区：
文献类型：
--
作者：
R. Braun;U. Schulz;C. Leyens;P. Hovsepian;A. Ehiasarian
摘要采用高功率脉冲磁控溅射技术在γ-TiAl基体材料上沉积了CrAlYN/CrN纳米多层涂层。在850 °C高温空气中，当暴露时间超过2 000次循环（1 h）时，氮化物涂层对γ-TiAl具有有效的抗氧化保护作用。在900 °C下也观察到高抗氧化性。在850 °C下暴露于空气中300 h后，与裸γ-TiAl合金相比，涂覆的拉伸试样表现出约70 MPa的疲劳强度降低。通过电子束物理气相沉积法制备的氧化锆面漆与具有氧氮化物外涂层的CrAlYN/CrN涂层具有良好的粘附性。在900 °C热循环条件下，该热障涂层系统在γ-TiAl基体上的寿命超过1 000次1 h循环。在氮化物涂层中的裂纹下方，衬底被氧化，并且形成具有柱状结构的外部氧化物层的突起。
Abstract CrAlYN/CrN nanoscale multilayer coatings were deposited on γ-TiAl substrate material using high power impulse magnetron sputtering technology. The nitride coating provided effective oxidation protection to γ-TiAl at 850 °C for exposure time periods exceeding 2 000 cycles of 1 h dwell time at high temperature in air. High oxidation resistance was also observed at 900 °C. After exposure to air at 850 °C for 300 h, coated tension specimens exhibited a reduction in fatigue strength of about 70 MPa compared to the bare γ-TiAl alloy. Zirconia topcoats produced by electron-beam physical vapour deposition were well adherent to the CrAlYN/CrN coating with an oxy-nitride overcoat. When thermally cycled at 900 °C, the lifetime of this thermal barrier coating system on γ-TiAl exceeded 1 000 1 h cycles. Below cracks in the nitride coating, the substrate was oxidised and protrusions of an outer oxide scale with columnar structure formed.