Movable Thermal Screen for Bridgman Directional Solidification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The Bridgman method for directional solidification of single-crystal parts does not achieve an optimal temperature gradient, leading to destabilization of the thermal gradient and potential flaws in the solidified parts due to fixed thermal screens that fail to stabilize the gradient at all stages of solidification.

Innovation Solution

An installation with movable thermal screens on either side of the mold, allowing the second thermal screen to follow the solidification front and stabilize the thermal gradient, and an additional narrower thermal screen to continue stabilization when the first screen cannot due to mold geometry constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a fixed thermal screen is used to stabilize the temperature gradient, then the thermal gradient is stabilized at certain moments of solidification, but the thermal gradient becomes destabilized at other moments when the solidification front moves away from the screen

Engineering Contradiction:

Improvethermal gradient stabilityVSAvoidadaptability to solidification front position

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent applies the dynamics principle by making the thermal screen movable instead of fixed. The thermal screen is coupled to the mold through a movement system that allows it to follow the solidification front during directional solidification. This dynamic adjustment ensures the thermal screen remains effective at stabilizing the temperature gradient throughout the entire solidification process, regardless of the solidification front's position.

Inventive Principle:

Principle #15Dynamics

2Stability of the object's composition

If a thermal screen is placed on one side of the mold, then the temperature gradient is stabilized on that side, but excessive cooling occurs on the opposite side

Engineering Contradiction:

Improvetemperature gradient stabilizationVSAvoidexcessive cooling on opposite side

Core Design Contradiction:

Stability of the object's compositionVSTemperature

Solution Approach 1:

The patent addresses this imbalance by placing thermal screens on both sides of the mold (first and second thermal screens on opposite sides). This asymmetric configuration ensures that both sides of the mold receive appropriate thermal management, preventing excessive cooling on the side opposite to the first thermal screen while maintaining stable temperature gradients throughout the mold.

Inventive Principle:

Principle #4Asymmetry

3Device complexity

If a single thermal screen is used, then the device complexity is low, but the thermal gradient cannot be stabilized throughout the entire solidification process

Engineering Contradiction:

Improvenumber of thermal screensVSAvoidcontinuous thermal gradient stabilization

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The patent applies segmentation by dividing the thermal management system into multiple independent thermal screens (first and second thermal screens) positioned on opposite sides of the mold. Each thermal screen can be independently controlled and moved, allowing for precise stabilization of the temperature gradient at different locations and times during the solidification process.

Inventive Principle:

Principle #1Segmentation

4Ease of manufacture

If the thermal screen is fixed with respect to the mold, then the implementation is simple, but the thermal gradient destabilizes when the solidification front moves away from the screen position

Engineering Contradiction:

Improveease of thermal screen implementationVSAvoidthermal gradient stability during solidification

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent transforms the static thermal screen into a dynamic component that moves with the solidification front. The movement system couples the thermal screen to the mold, enabling automatic tracking of the solidification front's position. This dynamic approach maintains thermal gradient stability throughout the entire solidification process while remaining relatively simple in implementation.

Inventive Principle:

Principle #15Dynamics

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

This approach ensures a stable thermal gradient throughout the solidification process, reducing excessive cooling and improving the quality and properties of the parts produced, such as turbomachine components.

Implementation Method 1

a first thermal screen fixed with respect to the enclosure and being situated on a first side of the mold, the heating zone being superimposed on the cooling zone along an axis of the enclosure

Methodology Applied

Scientific EffectThermal radiation blocking: Thermal Radiation

Implementation Method 2

The temperature of the hot zone can be maintained by radiation by susceptors heated by induction

Methodology Applied

Scientific EffectRadiation heating: Thermal Radiation

Implementation Method 3

a cold zone regulated to a temperature allowing solidification of the melted material. The temperature of the hot zone can be maintained by radiation by susceptors heated by induction. A thermal screen can be present at the border between the cold and hot zones. There exists a strong temperature gradient between these two zones

Methodology Applied

Scientific EffectDirectional solidification: Temperature Gradient

Implementation Method 4

a second thermal screen movable with respect to the mold, distinct from the first thermal screen and situated on a second side of the mold opposite to the first side

Methodology Applied

Scientific EffectThermal radiation blocking: Thermal Radiation

Data Source

PatentUS10562096B2Installation for manufacturing a part by implementing a Bridgman method

Publication Date: 2020.02.18 SAFRAN SA

AI summary

An installation for manufacturing a part by implementation of a Bridgman method includes in particular a mold intended to receive a melted material and a thermal screen movable with respect to the mold intended to be positioned in front of the solidification front during the directional solidification.