Nickel-Base Superalloy Composition for Crack-Resistant Additive Manufacturing

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Solution Overview

Problem

Nickel-base superalloys like CM247LC are unsuitable for additive manufacturing due to cracking and low tensile and creep ductility at high temperatures, making them sub-optimal for processes such as solidification and strain age cracking in reheated zones.

Innovation Solution

A novel nickel-base superalloy composition with adjusted components, including reduced Hf, C, Zr, and B content, and added Nb, to improve cracking behavior and high-temperature ductility, suitable for additive manufacturing processes like Laser Powder Bed Fusion and directed energy deposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional nickel-base superalloy CM247LC is used for additive manufacturing, then the alloy has good temperature capability, but it exhibits cracking during deposition and low tensile/creep ductility at high temperatures

Engineering Contradiction:
Improvetemperature capabilityVSAvoidcracking during deposition
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by modifying the chemical composition parameters of the nickel-base superalloy. Specifically, it adjusts the content ranges of key elements: Cr (8.0-12.0%), Co (9.0-11.0%), Mo (0.4-0.6%), W (9.0-10.0%), Ta (0.1-3.5%), Al (4.4-5.6%), Ti (0.1-1.0%), Hf (0.3-0.9%), C (0.01-0.06%), B (0.005-0.010%), Nb (0.1-0.6%), and Zr (0-0.005%). These compositional parameter changes resolve the contradiction by improving cracking resistance and high-temperature ductility while preserving temperature capability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional nickel-base superalloy CM247LC is used for additive manufacturing, then the alloy has good temperature capability, but it exhibits low tensile and creep ductility at high temperatures

Engineering Contradiction:
Improvetemperature capabilityVSAvoidtensile and creep ductility at high temperatures
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent resolves this contradiction through parameter changes in alloy composition. The specific adjustment of element contents, particularly optimizing the balance between strengthening elements (Al, Ti, Ta, Nb for γ' precipitation) and ductility-enhancing elements (Cr, Co, Mo, W), achieves improved tensile and creep ductility at high temperatures while maintaining the alloy's temperature capability. The controlled composition ensures adequate γ' phase for strength while preventing excessive brittleness.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If alloy composition is optimized for conventional casting processes, then the alloy has good castability, but it produces sub-optimal microstructure and properties for additive manufacturing

Engineering Contradiction:
ImprovecastabilityVSAvoidmicrostructure quality for additive manufacturing
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by developing a new composition specifically optimized for additive manufacturing processes. The composition differs from conventional casting-optimized alloys like CM247LC by controlling impurity levels (C: 0.01-0.06%, B: 0.005-0.010%, Zr: 0-0.005%) and adjusting alloying element ranges to achieve fine, uniform microstructure suitable for additive manufacturing. This resolves the contradiction by prioritizing microstructure quality for additive manufacturing while maintaining adequate manufacturability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3650565B1A nickel-base superalloy
Publication Date: 2024.09.25 ROLLS ROYCE PLC
  • EP3650565B1 patent drawingFigure 1~2
  • EP3650565B1 patent drawingFigure 3~4
  • EP3650565B1 patent drawingFigure 5

AI summary

The novel nickel-base superalloy useful in an additive manufacturing process or a powder-based manufacturing process comprises the following composition in wt%: Cr about 8.0 - about 12.0, Co about 9.0 - about 11.0, Mo about 0.4 - about 0.6, W about 9.0 - about 10.0, Ta about 0.1 - about 3.5, Al about 4.4 - about 5.6, Ti about 0.1 - about 1.0, Hf about 0.3 - about 0.9, C about 0.01 - about 0.06, B about 0.005 - about 0.010, Zr 0 - about 0.005, Nb about 0.1 - about 0.6, Mn 0 - about 0.05, S 0 - about 0.003, the balance nickel and incidental elements and unavoidable impurities, in which the total content of Al, Ta and Ti does not exceed 9.0 wt% and in which the total content of Nb and Ta does not exceed 2.4 at%.