Fluidized Powder Bed Sintering for Faster Gradient 3D Printing
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Solution Overview
Problem
Laser sintering technology for additive manufacturing is limited by the availability of powders with good flowability, high costs, limited preheating range, fabrication speed, temperature control issues, inefficient heat removal, and difficulty in producing articles with gradients in composition.
Innovation Solution
The system fluidizes a bed of powder and uses a directed energy beam to sinter particles in selected target areas, allowing for a wide range of powder types and compositions, efficient heat transfer, and continuous deposition, enabling the production of articles with complex structures and gradients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser sintering is used to additively manufacture articles, then complex three dimensional articles can be produced, but fabrication speed is limited by the roller step
Solution Approach 1:
The patent removes the roller component from the additive manufacturing system entirely. Instead of using a roller to deposit powder layers, the invention uses a fluidized bed where powder is deposited directly onto the build platform through fluidization, eliminating the mechanical roller step that limited fabrication speed.
Solution Approach 2:
The patent employs fluidization technology using gas flow to suspend and distribute powder particles. A fluidized bed chamber with gas distribution plates creates a pneumatic system that deposits powder uniformly without mechanical contact, replacing the roller-based mechanical deposition method.
2Manufacturing precision
If powder is preheated to improve sintering quality, then particle adhesion improves, but preheating range is limited by caking temperature
Solution Approach 1:
The patent changes the temperature parameter dynamically during the manufacturing process. The build platform temperature is varied through different stages: initial heating to facilitate powder deposition, then cooling or maintaining lower temperatures during sintering to prevent caking, and localized heating only where needed by the laser beam.
Solution Approach 2:
Instead of uniformly heating the entire powder bed, the patent applies heat locally only to the specific areas being sintered by the laser beam. The build platform may be heated to a moderate temperature to aid deposition, but high temperatures are confined to the localized sintering zone, preventing caking in the bulk powder.
3Ease of operation
If a quiescent powder bed is used, then temperature control is simplified, but heat removal from the fabrication process is inefficient
Solution Approach 1:
The patent changes the state of the powder bed from quiescent (static) to fluidized (dynamic). The fluidized state creates continuous particle motion and gas flow through the powder bed, dramatically enhancing heat transfer coefficients and enabling efficient heat removal from the sintering zone while maintaining temperature control through the fluidization process itself.
4Productivity
If traditional laser sintering is used, then article fabrication is achieved, but it is difficult to fabricate articles with gradient in composition
Solution Approach 1:
The patent enables different powder compositions to be introduced at different locations and times during the manufacturing process. The fluidized bed system allows for multiple powder sources or composition changes, enabling the laser to sinter different material compositions in different zones of the build platform, thus creating articles with spatial gradients in material properties.
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 the production speed, reduces costs, and allows for the creation of articles with specific gradient properties and improved temperature control, overcoming the limitations of traditional laser sintering methods.
Implementation Method 1
uses a directed energy beam to sinter particles in selected target areas
Implementation Method 2
selectively irradiating the powdered material. As a result of the irradiation, the polymer particle partially melts or melts the surface of the particle
Implementation Method 3
fluidizing a bed of powder and using a directed energy beam to join (e.g., sinter) the particles of the powder in selected target areas
Data Source
AI summary
A system, method and apparatus for additive manufacturing is disclosed. The method includes fluidizing particles with a medium to form a fluidized bed and additively manufacturing an article formed from the particles. The article has an open porous structure defining a plurality of pores and a plurality of fluid paths through the article. The method further includes flowing the particles and the medium through the fluid paths while the fluid paths are being formed. The article may be additively manufactured by selectively sintering the particles at target areas on the article which are near the surface of the fluidized bed.