Seed Crystal Seeding in Ceramic Mold Casting

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional methods for manufacturing turbine blades with intricate internal cooling passages and complex geometries are limited by positional precision and increased manufacturing time and expense, especially when using investment casting techniques.

Innovation Solution

The method involves seeding a preheated ceramic mold with a seed crystal body when loaded into a casting furnace, using a ceramic cone and shell mold configuration with an alignment feature, and applying a ceramic overcoat to form a casting assembly that allows for controlled crystallization and reduced defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a seed crystal is loaded into a preheated mold before firing, then the mold is ready for immediate casting, but the seed crystal is exposed to elevated temperatures causing oxidation and defects

Engineering Contradiction:

Improvecasting readinessVSAvoidseed oxidation

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The mold is preheated and prepared in advance, but the seed crystal is loaded only at the moment of casting rather than beforehand. This preliminary preparation of the mold allows immediate casting when the seed is introduced, eliminating prolonged exposure to high temperatures while maintaining productivity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The seed crystal is extracted from the high-temperature environment by loading it into the preheated mold only at the moment of casting, rather than leaving it in the heated mold during the firing process. This separation removes the seed from harmful thermal exposure while maintaining the mold's readiness

Inventive Principle:

Principle #2Taking out (Extraction)

2Adaptability or versatility

If conventional investment casting techniques are used for complex geometries, then manufacturing capability is achieved, but positional precision deteriorates and manufacturing time increases

Engineering Contradiction:

Improvecomplex geometry capabilityVSAvoidpositional precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention changes the fundamental parameter of how the mold is prepared and used. Instead of using traditional investment casting with wax patterns and ceramic shells that require multiple processing steps, the method uses a preheated reusable mold that maintains dimensional stability and positional precision while accommodating complex geometries

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The mold is preheated and prepared in advance with precise positioning features, eliminating the need for repeated positioning and alignment operations required in conventional investment casting. This preliminary preparation ensures consistent positional precision across multiple casting cycles

Inventive Principle:

Principle #10Preliminary action

3Productivity

If the seed crystal is exposed to elevated temperatures during mold preparation, then the mold can be loaded immediately, but defects are introduced into the cast component

Engineering Contradiction:

Improveloading speedVSAvoidcast component quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The seed crystal is extracted from the high-temperature firing process entirely. The mold is preheated and ready, but the seed is introduced only at casting time, removing it from the harmful thermal environment that causes oxidation and defects while maintaining immediate casting capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The preheated mold serves as an intermediary that maintains thermal readiness without requiring the seed crystal to be exposed to high temperatures. The mold's thermal energy is prepared in advance, but the seed is introduced only when needed, acting as a protected intermediary between the hot mold and the temperature-sensitive seed

Inventive Principle:

Principle #24Intermediary (Mediator)

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 reduces defects associated with seed oxidation and inclusion introduction, minimizes seed exposure to elevated temperatures, and facilitates direct loading of the mold into a firing furnace, thereby improving the precision and efficiency of casting complex components like turbine blades.

Implementation Method 1

pouring liquid metal into the mold such that the crystal seed portion contributes to controlled crystallization of the cast component

Methodology Applied

Scientific EffectCrystallization: Crystallisation

Implementation Method 2

seeding a preheated ceramic mold with a seed crystal body when loaded into a casting furnace

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS11014153B2Method for seeding a mold

Publication Date: 2021.05.25 GENERAL ELECTRIC CO

AI summary

A method for producing a cast component is provided. The method includes attaching a ceramic mold to a seed crystal body, the ceramic mold including a cavity defining the shape of the cast component and a seed crystal body interface having a complementary shape to the seed crystal body such that the seed crystal body may be capable of supporting the ceramic mold in a casting oven. The method also includes pouring a liquid metal into the mold such that the crystal seed portion contributes to controlled crystallization of the cast component.