Additive Ceramic Filter With Tortuous Channels

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional ceramic foam filters used in metal casting operations exhibit non-uniform and inconsistent pore sizes, leading to variations in metal flow rates and filtration efficiency, which negatively impact mold fill and cure times.

Innovation Solution

The method involves sintering a ceramic foam filter body to a temperature greater than the molten metal, creating multiple tortuous path channels with controlled geometry and varying diameters and areas, and applying a mixture of ceramic powder and binder using additive manufacturing to shape the filter body, including features like sinusoidal-shaped channels and multi-layer structures with different pore sizes and wettability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional ceramic foam filters are made by dipping polymer sponges in ceramic slurry and sintering, then the filter structure is formed, but the pore sizes become non-uniform and inconsistent

Engineering Contradiction:

Improvepore size uniformityVSAvoidfiltration efficiency consistency

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent replaces the conventional chemical/dipping-based manufacturing process with additive manufacturing technology. This allows for precise digital control of pore geometry, ensuring uniform and consistent pore sizes throughout the filter structure, directly resolving the non-uniformity issue inherent in traditional dip-coating methods

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the manufacturing parameters from empirical dip-coating variables to precisely controlled additive manufacturing parameters (layer thickness, extrusion rate, digital model dimensions). This enables exact reproduction of desired pore sizes and geometries, eliminating the variability caused by manual processing parameters

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If ceramic filters have non-uniform pore sizes, then the filter structure is simpler to manufacture, but the metal flow rate varies significantly

Engineering Contradiction:

Improvefilter production simplicityVSAvoidmetal flow rate consistency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

Additive manufacturing replaces traditional ceramic forming methods, enabling complex geometries with uniform pores to be manufactured just as easily as simple structures. The digital fabrication process maintains consistent flow characteristics while preserving manufacturing efficiency

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention creates homogeneous pore structures throughout the filter with uniform size distribution. This homogeneity ensures consistent metal flow rates across the entire filter surface, eliminating the flow variation problems caused by non-uniform conventional filters

Inventive Principle:

Principle #33Homogeneity

3Reliability

If conventional ceramic filters are used, then the filtration function is provided, but the mold fill and cure times are negatively impacted

Engineering Contradiction:

Improvefiltration functionVSAvoidmold fill and cure time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The invention optimizes flow parameters by creating controlled tortuous paths with specific geometry ratios. The channels are designed with gradual expansions and contractions that maintain laminar flow and prevent turbulence, allowing faster metal passage while preserving filtration effectiveness

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs curved, tortuous channel paths rather than straight lines. These smooth curved transitions guide metal flow through the filter efficiently, reducing flow resistance and preventing dead zones where inclusions might accumulate, thereby maintaining fast mold fill times

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 enhances filtration efficiency by creating localized changes in metal flow rates, effectively trapping inclusions and oxides, and allows for tailored filtration of different-sized objects across multiple layers, improving the consistency and quality of the casting process.

Implementation Method 1

sintering a filter body to a temperature greater than a molten metal to be filtered through the body

Methodology Applied

Scientific EffectSintering: Sintering

Data Source

PatentUS11992874B2Process to make a ceramic filter for metal casting

Publication Date: 2024.05.28 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method to manufacture a ceramic foam filter includes: sintering a filter body to a temperature greater than a molten metal to be filtered through the body; creating multiple tortuous path channels extending through the filter body individually having a repeated and controlled passage geometry creating a continuously changing diameter and area of a flow path through the multiple tortuous path channels causing localized increases and decreases in molten metal flow rate through the multiple tortuous path channels; and applying a mixture of at least one ceramic powder and at least one binder using additive manufacturing to shape the filter body including the multiple tortuous path channels.