Directional Divergence in Casting Solidification Interface

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Solution Overview

Problem

Existing casting processes are limited in furnace design due to the restriction that the solidification front can only be controlled in the direction of part motion, limiting the potential for creating single crystal microstructures with angular deviations.

Innovation Solution

A method and system that allow directional crystallization of components at angles significantly deviated from the movement direction by using a furnace with a solidification interface that traverses across the mold in a direction perpendicular to the movement, incorporating heat source and heat sink regions separated by a baffle, and featuring heat transfer modifications such as baffles and composition variations to maintain consistent cooling rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the solidification front is controlled by passing the part through a transition between heat sourcing and heat sinking, then the solidification direction is limited to the direction of motion of the part or a small angular departure, but this restriction limits potential furnace design possibilities

Engineering Contradiction:
Improvesolidification direction controlVSAvoidfurnace design possibilities
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent introduces a second direction (D2) for the solidification interface traversal that is deviated from the first direction (D1) of mold movement. This dimensional change allows the solidification front to progress at an angle relative to the mold motion, enabling single crystal growth in directions not aligned with the movement direction and significantly expanding furnace design possibilities.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Stability of the object's composition

If the solidification front moves through the material as the material solidifies, then the solidification direction is constrained to the main axis of the mold, but this limits the ability to create single crystal microstructures with angular deviations

Engineering Contradiction:
Improvesingle crystal microstructureVSAvoidcrystallization angle flexibility
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

By introducing the deviated second direction (D2) for solidification interface traversal, the patent enables single crystal growth in directions that are angularly deviated from the mold movement direction. This resolves the contradiction by allowing controlled single crystal formation while simultaneously providing flexibility in crystallization angle.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the directional parameters of the solidification process by introducing a deviated traversal direction for the solidification interface. This parameter change allows the solidification front to progress at an angle relative to the mold motion, enabling angular deviations in single crystal growth while maintaining compositional stability.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables the production of single crystal and equiaxed castings with controlled solidification fronts, allowing for more flexible furnace designs and consistent cooling rates, thereby expanding the possibilities in casting technology.

Implementation Method 1

A heat source region (110) maintains the molten casting material (116) in a liquid state

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

A heat sink region (108) cools the mold (102) or allows the mold (102) to cool, and contributes to the solidification of the molten casting material (116)

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 3

A solidification front (104) within the casting is illustrated, which advances in the second direction (105) as the mold (102) moves in the first direction (114)

Methodology Applied
Scientific EffectSolidification: Phase Change

Data Source

PatentEP2461925B1System, method, and apparatus for directional divergence between part motion and crystallization
Publication Date: 2020.04.29 ROLLS ROYCE CORP
  • EP2461925B1 patent drawingFigure 1~2

AI summary

A method includes providing a mold including a molten casting material, moving the mold in a first direction, and guiding a solidification interface across the mold in a second direction in response to the moving the mold. The second direction is deviated from the first direction, and the solidification interface includes a transition to a negative heat transfer region. The mold moves in the first direction at a constant speed, and the mold includes heat transfer features such that a solidification time of the molten casting material at the conditions of the solidification interface is approximately constant as a function of the second direction.