Creep induced precipitation of the (Cr,Mo)(5)B-3-type boride in gamma/gamma ' eutectic of a Ni-based superalloy
Creep induced precipitation of the (Cr,Mo)(5)B-3-type boride in gamma/gamma ' eutectic of a Ni-based superalloy
复制标题
DOI：
10.1016/j.matchar.2020.110569
复制
发表时间：
2020
影响因子：
4.7
通讯作者：
Ma Xiuliang
中科院分区：
文献类型：
--
作者：
Ge Hualong;Yang Yaqian;Zheng Shijian;Liu Kui;Ma Xiuliang
镍基高温合金的晶界硼偏析和硼化物形成是公认的。然而，在本研究中发现，在高温蠕变过程中，添加硼会导致ni基高温合金的γ/γ′共晶中形成高密度的纳米M5B3（其中M是Cr， Mo的混合物）颗粒。在γ/γ′共晶处析出的M5B3相与共晶保持明确的取向关系，分别为[001]γ/γ′//[001]M5B3， (020)γ/γ′//(130)M5B3。在高温蠕变过程中，这些纳米硼化物可以阻断位错滑移，导致γ/γ′共晶周围的应力集中，促进γ/γ′共晶/基体界面的裂纹萌生。
Boron segregation and boride formation at grain boundaries are generally accepted in Ni-based superalloys. However, the addition of boron was found to result in the formation of a high density of nanosized M5B3(where M is a mixture of Cr, Mo) particles in γ/γ′ eutectics of a Ni-based superalloy during high-temperature creep in this work. M5B3phase precipitated at γ/γ′ eutectics keeps a well-defined orientation relationship with the eutectics, which is [001]γ/γ′//[001]M5B3, (020)γ/γ′//(130)M5B3. And these nanosized borides could block dislocation slip, result in stress concentration surrounding γ/γ′ eutectics and facilitate crack initiation at γ/γ′ eutectic/matrix interface during the creep at high temperatures.