Effects of Boron and Zirconium on Grain Boundary Morphology and Creep Resistance in Nickel-Based Superalloy

Kang, Byung-Il; C.X.Han,; Shin, Young Hee; Youn, Jeong-Il; Kim, Young‐Jig

doi:10.1007/s11665-019-04419-y

Cited by 15 publications

(10 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been shown that the addition of boron to Ni-based superalloys could significantly influence the grain boundary precipitation [ 31 , 52 , 53 ]. B atoms are larger than those of the other interstitial atoms and smaller than those of the substitutional atoms in Ni-based superalloys.…”

Section: Resultsmentioning

confidence: 99%

Analysis of γ′ Precipitates, Carbides and Nano-Borides in Heat-Treated Ni-Based Superalloy Using SEM, STEM-EDX, and HRSTEM

et al. 2020

View full text Add to dashboard Cite

The microstructure of a René 108 Ni-based superalloy was systematically investigated by X-ray diffraction, light microscopy, energy-dispersive X-ray spectroscopy, and electron microscopy techniques. The material was investment cast in a vacuum and then solution treated (1200 °C-2h) and aged (900 °C-8h). The γ matrix is mainly strengthened by the ordered L12 γ′ phase, with the mean γ/γ′ misfit, δ, +0.6%. The typical dendritic microstructure with considerable microsegregation of the alloying elements is revealed. Dendritic regions consist of secondary and tertiary γ′ precipitates. At the interface of the matrix with secondary γ′ precipitates, nano M5B3 borides are present. In the interdendritic spaces additionally primary γ′ precipitates, MC and nano M23C6 carbides were detected. The γ′ precipitates are enriched in Al, Ta, Ti, and Hf, while channels of the matrix in Cr and Co. The highest summary concentration of γ′-formers occurs in coarse γ′ surrounding MC carbides. Borides M5B3 contain mostly W, Cr and Mo. All of MC carbides are enriched strongly in Hf and Ta, with the concentration relationship between these and other strong carbide formers depending on the precipitate’s morphology. The nano M23C6 carbides enriched in Cr have been formed as a consequence of phase transformation MC + γ → M23C6 + γ′ during the ageing treatment.

show abstract

Section: Resultsmentioning

confidence: 99%

Analysis of γ′ Precipitates, Carbides and Nano-Borides in Heat-Treated Ni-Based Superalloy Using SEM, STEM-EDX, and HRSTEM

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Figure 8a reveals two domains in the C and B contents. Carbides [12,[26][27][28]40,47,48,54,56,57,[63][64][65]80,81,104,106,108,111,137,143,[221][222][223][224] For a more intuitive representation and a table of the used references, readers are referred to the supporting information. are predominantly preferred above the isoline, below which borides and both, carbides and borides, are preferred.…”

Section: Solid-state Phase Transformationsmentioning

confidence: 99%

“…A minimal amount of B may be beneficial due to GB segregation [48,[77][78][79][80][81] as well as the capability of some carbides to dissolve small amounts of B. [26,221] Figure 8b reveals similar domains between Zr and B contents. Above the isoline, carbides are preferred, below which borides are preferred.…”

Section: Solid-state Phase Transformationsmentioning

confidence: 99%

See 1 more Smart Citation

Review of Microstructure–Mechanical Property Relationships in Cast and Wrought Ni‐Based Superalloys with Boron, Carbon, and Zirconium Microalloying Additions

et al. 2022

View full text Add to dashboard Cite

Cast and wrought Ni‐based superalloys are materials of choice for harsh high‐temperature environments of aircraft engines and gas turbines. Their compositional complexity requires sophisticated thermo‐mechanical processing. A typical microstructure consists of a polycrystalline γ‐matrix, strengthening Ni3(Al,Ti) γ′ precipitates, carbides (MC, M6C, and M23C6), borides (M2B, M3B2, and M5B3), and other inclusions. Microalloying additions of B, C, and Zr commonly improve high‐temperature strength and creep resistance, although excessive additions are detrimental. Grain boundary (GB) segregation may improve cohesion and displace embrittling impurities. Finely dispersed carbides and borides are desired to control grain size via GB pinning. However, excessive decoration of GBs may lead to failure during processing and in‐service. Hence, a systematic review on the roles of B, C, and Zr in cast and wrought Ni‐based superalloys is required. The current state of knowledge on GB segregation and precipitation is reviewed. Experimental and modeling results are compared across various processing steps. The impact of GB precipitation on mechanical properties is most well researched. Co‐precipitation in proximity to GBs interacting with local microstructure evolution and mechanical properties remains less explored. Addressing these gaps in knowledge allows a more complete understanding of processing–microstructure–properties relationships in advanced cast and wrought Ni‐based superalloys.

show abstract

“…Our previous study also attempted to discuss the effect of B and Zr. Trace amounts of B and Zr were added to a designed nickel-based superalloy, and the microstructure and creep-resistant properties were evaluated [27]. However, the effect of B and Zr had been partially investigated.…”

Section: Introductionmentioning

confidence: 99%

Microstructural Analysis on Grain Boundary of Boron– and Zirconium–Containing Wrought Nickel-Based Superalloys

Kang,

Lee,

Kim

et al. 2024

Crystals

View full text Add to dashboard Cite

Trace elements such as boron (B) and zirconium (Zr) can increase creep resistance in nickel-based superalloys. This study investigates the change of microstructures on the grain boundary (GB) in phase-controlled nickel-based superalloys through the addition of trace elements. The basis alloy without B and Zr has distributed micrometer-sized (Nb, Ti)C and Cr23C6 carbides at the GBs. Zr is detected alongside Nb and Ti within certain (Nb, Ti)C carbides and its addition increases the fraction of (Nb, Ti)C or (Nb, Ti, Zr)C carbides. B affects the formation of precipitates constructed by nanometer-sized precipitates, which are Cr23C6 carbides, Cr23(C, B)6 boro-carbides, and Cr-rich borides, surrounded by γ’ phases. This film structure, which includes nanometer-sized precipitates surrounded by γ’ phases, forms more continuously with the addition of B and Zr. It is constructed with precipitates of (Nb, Ti)C carbides and Cr23(C, B)6 boro-carbides surrounded by γ’ phases. Numerous nanometer-sized precipitates (i.e., (Nb, Ti)C and Cr23(C, B)6) are distributed alternately within the film structure. The effect of the addition of B and Zr is such that nucleation sites of each precipitate are formed simultaneously and alternately along the GBs. The experimental results were discussed by correlating them with the predicted fraction of stable phases depending on the temperatures of these alloys, using the JMatPro program.

show abstract

Effects of Boron and Zirconium on Grain Boundary Morphology and Creep Resistance in Nickel-Based Superalloy

Cited by 15 publications

References 13 publications

Analysis of γ′ Precipitates, Carbides and Nano-Borides in Heat-Treated Ni-Based Superalloy Using SEM, STEM-EDX, and HRSTEM

Analysis of γ′ Precipitates, Carbides and Nano-Borides in Heat-Treated Ni-Based Superalloy Using SEM, STEM-EDX, and HRSTEM

Review of Microstructure–Mechanical Property Relationships in Cast and Wrought Ni‐Based Superalloys with Boron, Carbon, and Zirconium Microalloying Additions

Microstructural Analysis on Grain Boundary of Boron– and Zirconium–Containing Wrought Nickel-Based Superalloys

Contact Info

Product

Resources

About