Support-free Ceramic Additive Manufacturing via High-Yield-Stress Slurry
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Solution Overview
Problem
Conventional additive manufacturing (AM) processes for ceramics require support structures to handle overhanging features, which introduce micro-cracks, increase fabrication time, and cause stress concentration, ultimately affecting the material properties of the final product.
Innovation Solution
The method employs a highly loaded ceramic slurry with pseudoplastic flow behavior and high yield stress to support overhanging features without building any extra structures, using a digital micro-mirror device to project light patterns and cure the slurry, thereby maintaining the shape and position of the ceramic part.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If support structures are used in conventional additive manufacturing for ceramics, then overhanging features can be fabricated, but micro-cracks and stress concentration are introduced, affecting material properties
Solution Approach 1:
The invention removes support structures entirely from the fabrication process. By using a high-yield-stress ceramic slurry formulation, the process extracts the harmful support structures while maintaining the capability to fabricate overhanging features through the slurry's inherent structural support properties during curing
Solution Approach 2:
The invention changes the rheological parameters of the ceramic slurry, specifically increasing the yield stress to a critical level that allows the slurry to support its own weight and overhanging features during the photopolymerization process, eliminating the need for external support structures
2Adaptability or versatility
If support structures are used in conventional additive manufacturing for ceramics, then overhanging features can be supported, but fabrication time increases due to additional structure creation and removal
Solution Approach 1:
The invention extracts and eliminates the support structure creation and removal steps from the fabrication process. By using modified ceramic slurry with enhanced yield stress, complex geometries are fabricated directly without requiring temporary support structures, thereby reducing total fabrication time
3Ease of manufacture
If conventional ceramic slurry is used, then the process is simple, but the slurry cannot support overhanging features without additional structures
Solution Approach 1:
The invention modifies the rheological parameters of the ceramic slurry by adjusting composition and formulation to achieve a critical yield stress threshold. This parameter change enables the slurry to support overhanging features while maintaining ease of manufacture through a streamlined single-step photopolymerization process
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 allows for the fabrication of ceramic components with complex geometries without support structures, reducing the risk of cracks and stress concentration, and improving the material properties by eliminating the need for additional support structures.
Implementation Method 1
A first layer of the ceramic slurry is cured to form a first cured ceramic layer
Implementation Method 2
The slurry has a viscosity ranging from about 3 Pas to about 500 Pas
Data Source
AI summary
According to various embodiments, a system for forming a ceramic part includes a chamber having a first closed end and a second end defining an opening. The platform is disposed within the chamber and adapted to move vertically in a z-direction between the first closed end and the second end. An applicator is adapted to move laterally in an x-y direction. The applicator includes a beveled edge. A light source is positioned in line with the second end of the chamber. A digital micro-mirror device is positioned between the light source and the second end of the chamber. The shutter is movable between a first open position and a second open position. A first image is projected when the digital micro-mirror device is in the first open position and a second image, different than the first image is projected when the digital micro-mirror device is in the second open position.