Shear-Thinning Ceramic Ink for Additive Manufacturing
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Solution Overview
Problem
Ceramic materials pose challenges in additive manufacturing due to their poor flowability, making it difficult to extrude them through nozzles and form 3D structures with sufficient ceramic concentration and complex geometries.
Innovation Solution
A ceramic-based ink with a high volume percentage of ceramic particles and a viscosifier is formulated to achieve shear-thinning rheological properties, allowing for the extrusion and deposition of ceramic materials in additive manufacturing processes, such as direct ink writing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional ceramic materials are used in additive manufacturing, then the ceramic material concentration can be high, but the material cannot flow sufficiently to be extruded from a nozzle
Solution Approach 1:
The patent changes the rheological parameters of the ceramic slurry by adding specific additives (viscosifiers and dispersants) to modify the flow behavior. The slurry is formulated to exhibit shear-thinning behavior where viscosity decreases under shear stress during extrusion, enabling flow through the nozzle while maintaining high ceramic content. The viscosity is controlled to be within a specific range (10-1000 Pa·s) to balance extrudability and shape retention.
Solution Approach 2:
The patent creates a composite slurry system combining ceramic particles with a liquid binder and functional additives. This composite formulation allows the ceramic material to achieve both high concentration (solids loading of 40-80 vol%) and improved flow characteristics through the synergistic interaction between components, particularly the viscosifier that provides shear-thinning behavior.
2Quantity of substance
If ceramic slurry with high ceramic content is extruded, then the ceramic material concentration in the printed structure is high, but the extruded material cannot retain its shape
Solution Approach 1:
The patent optimizes the viscosity parameter of the slurry to a specific range (10-1000 Pa·s) that simultaneously enables extrusion through the nozzle and shape retention after deposition. The shear-thinning behavior ensures low viscosity during extrusion (under shear stress) and high viscosity after extrusion (at rest), allowing the extruded material to maintain its geometric configuration without sagging or deforming.
Solution Approach 2:
The patent introduces a binder and viscosifying agents as intermediary substances between the ceramic particles. These intermediaries provide the necessary rheological properties that enable both flow during extrusion and shape retention after deposition. The binder holds the ceramic particles together in the extruded state, while the viscosifier controls the flow behavior during the extrusion process.
3Stability of the object's composition
If the viscosity of the ceramic slurry is increased to improve shape retention, then the material can maintain its form, but the material cannot be extruded from the nozzle
Solution Approach 1:
The patent employs dynamic viscosity control through shear-thinning behavior. The slurry viscosity is not fixed but changes dynamically based on the applied shear stress: during extrusion when shear stress is high, viscosity decreases to enable flow through the nozzle; after extrusion when shear stress is removed, viscosity increases to maintain shape retention. This dynamic property resolves the contradiction between extrudability and shape stability.
Solution Approach 2:
The patent formulates the slurry with viscosifying agents that create non-Newtonian flow behavior, specifically shear-thinning characteristics. This allows the viscosity parameter to change based on the flow conditions: low viscosity under the high shear rates experienced during nozzle passage, and high viscosity at rest or under low shear conditions after extrusion, thereby enabling both extrusion and shape retention.
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 ink enables the creation of 3D printed bodies with high ceramic content and complex geometries, maintaining shape and stability during and after deposition, and can be infiltrated with other materials to form robust components.
Implementation Method 1
The ink is formulated with ceramic particles and a viscosifier, and a solid loading of the ceramic particles has a high volume percentage and tailored to provide rheological properties to obtain shear thinning
Data Source
AI summary
An ink, and products formed from the ink, formulated at least in part from ceramic particles. The ink is formulated so that it can be used in additive manufacturing processes to form three-dimensional printed bodies. The three-dimensional printed bodies can have graded density and can be infiltrated by an infiltration material.