Multi-scale Study of the Formation and Evolution of M_6C Carbides in High-Tungsten Superalloys

IMR OpenIR

	Multi-scale Study of the Formation and Evolution of M_6C Carbides in High-Tungsten Superalloys
	Fei Xiang; Sheng Naicheng; Sun Shijie; Fan Shigang; Yu Jinjiang; Hou Guichen; Li Jinguo; Zhou Yizhou; Sun Xiaofeng
	2024
发表期刊	ACTA METALLURGICA SINICA(ENGLISH LETTERS)
ISSN	1006-7191
卷号	37 期号:12 页码:1995-2007
摘要	The formation and evolution of M_6C carbides in high-W superalloy following solution treatment was investigated at different temperatures. Initially, during solid solution treatment, MC and M_6C carbides was precipitated in the alloy. As the temperature increased, the morphology of M_6C carbides transitioned from granular to needle-like. During the solution treatment at 1255 °C, the MC carbides degraded and transformed into M_6C carbides, forming a symbiotic relationship between them. Nonetheless, no clear orientation relationship was observed between the two types of carbides. After further increasing the temperature to 1270 °C, the precipitation of needle-like M_6C carbides in the dendrite arm was confirmed. This was supported by electron probe X-ray micro-analyzer and selected area electron diffraction patterns. Subsequently, a detailed examination of the three-dimensional morphology and orientation relationship of the needle-like phase with the matrix was carried out using focused-ion-beam and transmission electron microscopy techniques. The results indicated that the flat interface of the needle phase exhibited a specific orientation relationship with the matrix. However, in the three-dimensional plane, the interfaces between the needle-like phase and the matrix were not straight. Furthermore, no clear orientation relationship between the non-straight interfaces and the matrix was observed. As the solution temperature increased, the tensile properties at room temperature progressively decreased, while the stress rupture properties peaked at 1260 °C, suggesting that the alloy demonstrated its optimal comprehensive performance at this temperature. A subsequent analysis was conducted on the longitudinal section of the fracture using electron backscattered diffraction. The results showed a noticeable concentration of stress at the interface between MC and M_6C carbides, which ultimately led to crack initiation at this interface. In addition, as the solid solution temperature increased, the quantity of symbiotic phases also increased. This phenomenon led to the initiation of cracks at multiple locations, which then propagated and interconnected. As a consequence, the tensile properties and stress rupture life of the alloy progressively deteriorated.
关键词	Superalloys Tungsten Solution treatment Carbides Mechanical properties
语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/179688
专题	中国科学院金属研究所
作者单位	中国科学院金属研究所
推荐引用方式 GB/T 7714	Fei Xiang,Sheng Naicheng,Sun Shijie,et al. Multi-scale Study of the Formation and Evolution of M_6C Carbides in High-Tungsten Superalloys[J]. ACTA METALLURGICA SINICA(ENGLISH LETTERS),2024,37(12):1995-2007.
APA	Fei Xiang.,Sheng Naicheng.,Sun Shijie.,Fan Shigang.,Yu Jinjiang.,...&Sun Xiaofeng.(2024).Multi-scale Study of the Formation and Evolution of M_6C Carbides in High-Tungsten Superalloys.ACTA METALLURGICA SINICA(ENGLISH LETTERS),37(12),1995-2007.
MLA	Fei Xiang,et al."Multi-scale Study of the Formation and Evolution of M_6C Carbides in High-Tungsten Superalloys".ACTA METALLURGICA SINICA(ENGLISH LETTERS) 37.12(2024):1995-2007.