梁静静
,
朱明
,
袁忠华
,
王君武
,
金涛
,
孙晓峰
,
胡壮麒
金属学报
doi:10.3724/SP.J.1037.2012.00603
利用Thermo-Calc热力学计算软件和TTNi7镍基高温合金数据库,研究了Re元素对Ni-20Cr-10Al-20Co合金体系相组成的影响规律.在热力学计算的基础上,设计了4组不同Re含量的NiCoCrAlY涂层合金,进行了不同温度的热暴露实验.研究结果表明,Re的添加,小幅度地提高了β-NiA1相的含量,且改变了Cr在各相中的分配,促进了富Cr的低温稳定相σ和高温稳定相α-Cr的析出,且σ→α-Cr的相变温度随Re含量的增加而升高.此外,实验结果还显示,Re的添加降低了γ'-Ni3Al→ γ-Ni的相变温度.对比计算结果和实验结果可发现,TTNi7数据库对MCrAlY合金在相组成演变规律方面的预测与实验结果符合较好,但在具体的相变温度方面,如γ'-Ni3Al→γ-Ni和σ→α-Cr的相变温度,与实验结果还存在较大偏差.
关键词:
NiCoCrAlY
,
相组成
,
Re
,
热力学计算
季强
,
宋鹏
,
王逸群
,
廖红星
,
陆建生
功能材料
doi:10.3969/j.issn.1001-9731.2016.04.015
高温服役过程中热障涂层的MCrAlY粘结层形成致密的氧化铝层,从而提高了涂层和基体的抗氧化性能。利用等离子喷涂制备的热障涂层,其粘结层中的 Co 与 Ni 的含量和界面微观结构是影响氧化的重要因素。通过在Ni基高温合金基体上利用低压等离子喷涂(LPPS)分别制备粘结层为 CoNiCrAlY和 NiCoCrAlY的热障涂层进行高温循环氧化实验,比较研究了这两种热障涂层在1050℃下的循环氧化寿命和失效特征。研究表明粘结层表面形貌对氧化物的生长具有重要影响,其中CoNiCrAlY粘结层更易在TGO 层中形成尖晶石氧化物,最终无法形成连续的Al2 O3层,导致涂层失效,而NiCoCrAlY粘结层表现出不同的失效方式。同时,粘结层和基体中Ni、Co等元素在氧化过程中存在强烈的互扩散,Co与 Ni 含量对两种涂层 BC/基体界面处宏观空洞的生长产生了不同影响。
关键词:
热障涂层
,
CoNiCrAlY
,
NiCoCrAlY
,
热循环
,
扩散
,
寿命
耿林
,
孟庆武
,
郭立新
材料工程
doi:10.3969/j.issn.1001-4381.2005.12.011
分别以NiCrBSi和NiCoCrAlY为预涂粉,采用CO2激光器,在Ti-6Al-4V合金表面进行激光熔覆镍基合金涂层的研究.通过X射线衍射仪(XRD)、扫描电镜(SEM)和能谱仪(EDS)对涂层进行分析,对比两种镍基合金粉的激光熔覆性能.分析发现, NiCrBSi涂层组织以γ-Ni为基体,含有Ni3B,TiB2,TiC,CrB等多种增强相,而NiCoCrAlY涂层组织主要为固溶多种元素的Ni基过饱和固溶体.NiCoCrAlY涂层组织以固溶强化和细晶强化为主,NiCrBSi涂层组织以第二相强化为主.虽然NiCoCrAlY粉比NiCrBSi粉的激光吸收率高,可以得到较厚的涂层,但是含有多种硬质增强相的NiCrBSi涂层硬度高于NiCoCrAlY涂层.
关键词:
激光熔覆
,
涂层
,
NiCrBSi
,
NiCoCrAlY
,
钛合金
J.J. Liang
材料科学技术（英）
MCrAlY can serve as stand-alone overlay coatings or bond coats in thermal barrier coating systems, and its properties play a vital role in determining the performance of these coating systems. In order to further understand the behavior of MCrAlY coatings, several NiCoCrAlY model alloys with different levels of Re (0.3 wt%, 6 wt%, and 9 wt%) were investigated. Microstructural observation showed the addition of Re promoted the precipitation of Cr-rich phases, such as α-Cr and σ. The presence of α-Cr lowered the coefficient of thermal expansion (CTE) of the coating alloys, which could reduce the CTE mismatch at the scale-metal interface. The solid solution strengthening effect of Re is responsible for an increase in Rockwell hardness of the coating alloys. But the isothermal oxidation resistance at 1100°C was deteriorated due to the precipitation of brittle α-Cr phase, a phase of inferior oxidation resistance compared with β-NiAl and γ-Ni.
关键词:
NiCoCrAlY
J.J. Liang
材料科学技术（英）
MCrAlY can serve as stand-alone overlay coatings or bond coats in thermal barrier coating systems, and
its properties play a vital role in determining the performance of these coating systems. In order to further
understand the behavior of MCrAlY coatings, several NiCoCrAlY model alloys with di®erent levels of Re
(0.3 wt%, 6 wt%, and 9 wt%) were investigated. Microstructural observation showed the addition of Re
promoted the precipitation of Cr-rich phases, such as ®-Cr and ¾. The presence of ®-Cr lowered the coe±cient
of thermal expansion (CTE) of the coating alloys, which could reduce the CTE mismatch at the scale-metal
interface. The solid solution strengthening e®ect of Re is responsible for an increase in Rockwell hardness of
the coating alloys. But the isothermal oxidation resistance at 1100oC was deteriorated due to the precipitation
of brittle ®-Cr phase, a phase of inferior oxidation resistance compared with ¯-NiAl and °-Ni.
关键词:
NiCoCrAlY
