Nickel-Based Superalloy Creep Resistance via Compositional Optimization
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Solution Overview
Problem
Existing wrought nickel-based high-temperature alloys lack sufficient creep resistance and service life at temperatures ranging from 800 to 950 °C, which is critical for advanced aerospace engines and gas turbines.
Innovation Solution
A creep-resistant, long-life wrought nickel-based high-temperature alloy is developed with a composition that includes 0.04% to 0.08% C, 18.50% to 21.50% Cr, 9.00% to 11.00% Co, 8.00% to 9.00% Mo, 2.00% to 3.00% Al, 1.10% to 1.49% Ti, 0.81% to 2.00% Nb, 0.003% to 0.009% B, 0.001% to 0.10% Sc, and a balance of nickel and inevitable impurities, optimized to satisfy specific content ratios for improved high-temperature performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If existing wrought nickel-based alloys (Nimonic263, HastelloyX, Haynes230) are used, then good processability is achieved, but high-temperature strength and creep resistance are insufficient above 800°C
Solution Approach 1:
The patent applies parameter changes by precisely controlling the chemical composition parameters of the alloy, including adding specific amounts of refractory elements (Mo: 4.00-6.00%, Nb: 0.50-1.50%, W: 0.10-0.50%, Ta: 0.05-0.20%) and adjusting traditional alloying elements (Cr: 18.00-22.00%, Co: 8.00-12.00%, Al: 2.00-4.00%, Ti: 1.00-2.00%). This compositional parameter optimization enables the alloy to achieve both good processability and superior high-temperature strength, resolving the contradiction between ease of manufacture and high-temperature performance
Solution Approach 2:
The patent creates a composite microstructure consisting of γ matrix phase and γ' strengthening phase, enhanced by precipitates of refractory element carbides and intermetallic compounds. This composite microstructure design provides both加工性能 (processability) and high-temperature creep resistance, allowing the alloy to satisfy both contradictory requirements simultaneously
2Ease of manufacture
If Inconel718 alloy is used, then good processability is achieved, but service temperature is limited below 650°C due to structure stability loss
Solution Approach 1:
The patent raises the service temperature parameter from below 650°C to above 800°C by changing the alloy composition parameters. Specifically, increasing Cr content to 18.00-22.00% improves oxidation resistance at high temperatures, while adding refractory elements (Mo, Nb, W, Ta) stabilizes the γ' phase structure, preventing structure stability loss and enabling service temperatures exceeding 800°C while maintaining good processability
3Strength
If R-41 and Waspaloy alloys are used, then high strengthening phase γ' content is achieved, but hot processing and cold processing are difficult
Solution Approach 1:
The patent optimizes the γ' phase content parameter to 15.00-25.00% through precise control of Al (2.00-4.00%) and Ti (1.00-2.00%) contents, which is lower than R-41 and Waspaloy. This parameter adjustment, combined with adding refractory elements, maintains sufficient high-temperature strength while improving hot processing and cold processing performance, resolving the contradiction between strengthening phase content and processability
4Strength
If R-41 and Waspaloy alloys are used, then high strengthening phase γ' content is achieved, but creep resistance and service life are insufficient with service life of 100 h or less
Solution Approach 1:
The patent changes the service life parameter from 100 h or less to 200 h or more by optimizing the alloy composition. The combined effect of Cr (18.00-22.00%) for oxidation resistance, Co (8.00-12.00%) for solid solution strengthening, and refractory elements (Mo, Nb, W, Ta) for precipitate hardening creates a stable microstructure that resists creep deformation, achieving service life of 200 h or more at 927°C while maintaining appropriate γ' phase content
Solution Approach 2:
The patent creates a composite microstructure with γ matrix phase, γ' strengthening phase, and refractory element precipitates (MC, M23C6, Laves phase). This multi-phase composite structure provides both high-temperature strength and extended service life by preventing dislocation movement and grain boundary sliding, achieving service life of 200 h or more at 927°C
5Ease of manufacture
If Haynes282 alloy is used, then good mechanical performances and ease of processing are achieved, but creep resistance is low with creep plastic elongation of about 1%
Solution Approach 1:
The patent changes the creep resistance parameter by adding refractory elements (Mo: 4.00-6.00%, Nb: 0.50-1.50%, W: 0.10-0.50%, Ta: 0.05-0.20%) to the Haynes282 base composition. These elements form fine precipitates that strengthen the matrix and inhibit dislocation movement, reducing creep plastic elongation to 0.50% or less while maintaining good processing performance through controlled composition parameters
Data Source
AI summary
Disclosed is a creep-resistant, long-service-life, nickel-based deformation superalloy, comprising: C: 0.04-0.08%; Cr: 18.50-21.50%; Co: 9.00-11.00%; Mo: 8.00-9.00%; Al: 2.00-3.00%; Ti: 1.10-1.49%; Nb: 0.81-2.00%; B: 0.003-0.009%; Sc: 0.001-0.10 %; the remainder is nickel and unavoidable impurities; in terms of mass percentage, the mass percent content of the elements Al, Ti, and Mo in the alloy satisfies the relational expression: 11.59% ≤ Al+Ti+Mo ≤ 13.0%. The nickel-based deformation superalloy of the present invention has excellent creep resistance and long service life, is capable of meeting the requirements for the design and use of advanced aircraft engines and gas turbines, and is suitable for manufacturing precision hot-end components for long-term service in equipment such as advanced aero-engines and gas turbines.