Porous Substrate Mold for Uniform Casting Solidification

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing directional solidification methods fail to produce castings with uniform microstructure and low internal stresses, often resulting in waste and additional manufacturing steps due to the need to separate excess material from the mold.

Innovation Solution

A mold design with a substrate having holes that allow coolant to flow through while preventing molten metal from passing through, combined with a coolant manifold for controlled cooling and a gate system to manage molten metal flow, ensuring a uniform solidification rate and reduced stress within the casting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a bottom plate is used in the mold for directional solidification, then the solidification direction is controlled, but the plate must be cut away or melted to separate the casting from the mold, resulting in waste and additional manufacturing steps

Engineering Contradiction:
Improvesolidification direction controlVSAvoidwaste material
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The mold bottom is designed with a porous substrate that allows coolant to pass through while preventing molten metal from penetrating. This eliminates the need for a separate bottom plate that requires removal, thereby reducing waste and additional manufacturing steps while maintaining directional solidification control

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention extracts the cooling function from a separate bottom plate and integrates it directly into the mold bottom structure. This eliminates the need for the bottom plate to be removed or melted away, as it becomes an integral part of the mold that remains with the casting

Inventive Principle:
Principle #2Taking out (Extraction)

2Manufacturing precision

If a bottom plate is used in the mold, then directional solidification is achieved, but additional steps are required to separate the casting from the plate

Engineering Contradiction:
Improvesolidification direction controlVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The porous substrate in the mold bottom enables direct integration of the cooling system into the mold structure, eliminating the need for separate bottom plate removal steps and improving manufacturing efficiency

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention merges the bottom plate function with the mold structure itself, creating an integrated system where the mold bottom serves both as the cooling surface and the release surface, thereby eliminating additional separation steps

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If cooling is applied to achieve directional solidification, then the casting structure is improved, but the cooling rate must be precisely controlled to avoid non-uniform microstructure and high internal stresses

Engineering Contradiction:
Improvecasting microstructure uniformityVSAvoidcooling control system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The porous substrate provides uniform distribution of coolant across the mold bottom surface, ensuring consistent cooling rates throughout the casting and producing a uniform microstructure without requiring complex control systems

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention applies local quality by using a porous substrate that provides uniform cooling characteristics across the entire mold bottom surface, ensuring consistent solidification conditions throughout the casting

Inventive Principle:
Principle #3Local quality

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

The method achieves a uniform microstructure and reduced internal stresses in castings, minimizing waste and the need for stress relief, while maintaining a controlled cooling rate for efficient solidification.

Implementation Method 1

spraying a coolant against the bottom of the mold cavity through the holes

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP2218527B1Method and apparatus for unidirection solidification of castings
Publication Date: 2013.01.02 ALCOA INC
  • EP2218527B1 patent drawingFigure 1
  • EP2218527B1 patent drawingFigure 2
  • EP2218527B1 patent drawingFigure 3

AI summary

Molten metal is injected uniformly into a mold from a feed chamber in a horizontal or vertical direction at a con-trolled rate, directly on top of the metal already within the mold. A cooling medium is applied to the bottom surface of the substrate, with the type and flow rate of the cooling medium being varied to produce a controlled cooling rate throughout the casting process. The rate of introduction of molten metal and the flow rate of the cooling medium are both controlled to produce a relatively uniform solidification rate within the mold, thereby producing a uniform microstructure throughout the casting, and low stresses throughout the casting. A multiple layer ingot product is also provided comprising a base alloy layer and at least a first additional alloy layer, the two layers having different alloy compositions, where the first additional alloy layer is bonded directly to the base alloy layer by applying the first additional alloy in the molten state to the surface of the base alloy while the surface temperature of the base alloy is lower than the liquidus temperature and greater than eutectic temperature of the base alloy - 50 degrees Celsuis.