摘要
采用d电子理论(Md法)和电子空穴(Nv法)的合金设计方法,利用定向凝固技术制备一种含大量W、Mo难溶元素,含4%Ru的镍基单晶高温合金,并对其进行高温蠕变性能测试及组织形貌观察。结果表明,合金经完全热处理后,γ'相以共格方式镶嵌在γ基体中,尺寸约为0.4μm,可以看到合金无TCP相(拓扑密排相)析出。在137MPa、1020℃条件下,其蠕变寿命为315h,较DD403高温合金蠕变寿命提高31.8%,蠕变伸长量提高13.0%。合金在高温蠕变期间γ'相形成筏状结构,随蠕变进行,筏状结构扭曲并发生断裂,直至形成宏观裂纹,最终导致试件断裂,这是镍基单晶高温合金的断裂机制。
Based on Md and Nv methods for alloy composition and directional solidification technique,the paper described the preparation of a single crystal nickel based superalloy containing a large amount of W and Mo as well as 4% Ru,it also presented high-temperature creep testing and microstructure observation. The results showed that the cubical γ＇ phase embedded coherently in the γ matrix with the size of 0. 4μm after fully heat heated and TCP phase precipitation was not found.The creep lifetime of the alloy was 315 h at 137 MPa /1020℃,an increase by 31. 8% in creep lifetime and 13. 0% in creep elongation higher than DD403 high temperature alloy. During high temperature creep,the raft structure was formed in the γ＇phase; the raft structure was twisted and broken up,forming marco-crack and resulting in fracture on the sample. The paper pointed out that the said was fracture mechanism of the superalloy.
出处
《有色金属加工》
CAS
2016年第2期21-24,共4页
Nonferrous Metals Processing
基金
青年项目自然科学(QNL201513)
关键词
元素Ru
镍基单晶高温合金
蠕变性能
TCP相
the Ru element
single crystal nickel based superalloy
creep properties
TCP phase
