Segmented 3D Printed Counterform for Uniform Sintering
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Solution Overview
Problem
Existing sintering techniques face challenges in achieving uniform densification and easy removal of complex-shaped parts due to heterogeneity and difficulties in removing parts with undercuts and tapers from molds, leading to material loss and geometric defects.
Innovation Solution
A counterform produced using digitally controlled 3D additive printing is used, with increased size to compensate for material shrinkage during sintering, allowing for homogeneous densification and easy separation of complex shapes by dividing the counterform into portions along a joint plane, facilitating the removal of parts with undercuts and tapers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If uniaxial pressure sintering is used to manufacture parts of complex shape, then densification is achieved rapidly, but heterogeneity of densification occurs in regions of different thickness
Solution Approach 1:
The counterform is divided into multiple portions that can be assembled together, allowing each portion to be optimized for uniform densification while maintaining the capability to produce complex-shaped parts with varying thicknesses
Solution Approach 2:
The invention transitions from traditional mold design to a modular counterform system where portions can be assembled in different configurations, adding a dimensional aspect of modularity to solve the densification uniformity problem
2Ease of manufacture
If traditional molds are used for complex shapes with undercuts and tapers, then parts can be formed, but removal of parts from the mold is difficult and causes material loss
Solution Approach 1:
The counterform is segmented into removable portions that can be separated from the sintered part, enabling easy removal of complex-shaped parts with undercuts and tapers without damaging the part or losing material
Solution Approach 2:
Instead of designing molds that retain parts, the invention uses a counterform system where portions are deliberately designed to be removed after sintering, inverting the traditional approach to part removal
3Ease of operation
If multiple counterforms are used to avoid removal problems, then part removal is facilitated, but device complexity and manufacturing steps increase
Solution Approach 1:
The counterform is divided into a manageable number of portions that can be assembled and removed systematically, reducing the complexity compared to using multiple complete counterforms while still facilitating easy part removal
Solution Approach 2:
Multiple counterform portions are combined into a single integrated system that functions as one removable assembly, reducing the number of separate tools needed while maintaining ease of operation
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 method ensures higher homogeneity of porosity and geometric precision in the manufactured parts, reducing material loss and defects, and simplifies the design and assembly process by eliminating the need for multiple molds and specialized tools.
Implementation Method 1
the counterform is formed of successive layers deposited by means of digitally controlled three-dimensional (3D) additive printing
Implementation Method 2
consolidating a volume of ceramic, polymer or metal powders in a conductive mold in order to rapidly obtain finely microstructured dense materials. This consolidation is achieved by means of the simultaneous application of a load (under a high uniaxial pressure exerted on the mold, for example of the order of 100 MPa) and heating, of the order of 500° C. to 2000° C.
Implementation Method 3
high-pressure spark sintering known as SPS (spark plasma sintering)
Implementation Method 4
the size of the counterform being increased by a density stretch factor that compensates for a shrinkage in the size of the part to be manufactured
Data Source
AI summary
A method for producing a counter-form (20) for manufacturing a part having a complex shape (24) by pressure sintering densification. The counter-form (20) is formed from successive layers produced by numerically-controlled three-dimensional (3D) additive printing according to the following steps: numerically recording a three-dimensional negative of the part to be produced (24) in a control unit of a three-dimensional additive printing system in order to constitute the positive form of the counter-form to be produced; producing the counter-form (20) using a 3D additive printing technique. The part having a complex shape (24d) is then manufactured by pressure sintering, then separated from the counter-form which is also sintered (20).