Composite Grains for Additive Manufacturing
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Solution Overview
Problem
Current methods for synthesizing multi-material powders for additive manufacturing and surface treatment face challenges such as inhomogeneous dispersion, intragranular porosity, and limited functionalization, particularly with techniques like co-grinding and spray-drying, which result in powders unsuitable for these applications due to morphology and structural issues.
Innovation Solution
A method involving the functionalization of support particles with smaller functionalization particles to create composite grains with a core-envelope structure, enhancing homogeneity, reactivity, and densification, using a recirculating fluidized bed reactor or high-energy mechanical reactor to achieve a specific surface layer and controlled particle size distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If co-grinding (mechanosynthesis) is used to produce multi-material powders, then composite grains with wide composition latitude can be obtained, but the morphology and particle size are not favorable for additive manufacturing applications
Solution Approach 1:
The invention changes the particle size parameter by using nanoscale functionalization particles (1-100 nm) deposited onto larger support particles (1-100 μm), creating a core-envelope structure that maintains favorable morphology while achieving wide compositional versatility through the functionalization layer
Solution Approach 2:
The invention segments the composite grain into two distinct parts: a support particle core that provides favorable morphology and size for additive manufacturing, and a functionalization particle envelope that provides compositional versatility and functional properties
2Shape
If spray-drying is used to produce multi-material powders, then spherical morphology can be obtained, but intragranular porosity and organic binders make them unsuitable for additive manufacturing
Solution Approach 1:
The invention extracts and eliminates the problematic organic binder and intragranular porosity by using a direct deposition approach where inorganic functionalization particles are deposited onto support particles without requiring organic binders, achieving dense spherical morphology suitable for additive manufacturing
Solution Approach 2:
The invention creates a composite material structure where inorganic functionalization particles form an envelope around inorganic support particles, eliminating the need for organic binders while maintaining spherical morphology and achieving density suitable for additive manufacturing
3Manufacturing precision
If CVD technology is used to synthesize multi-material powders, then deposits can be obtained on grain surfaces, but the process is neither technically nor economically favorable due to toxicity and cost of precursors
Solution Approach 1:
The invention replaces expensive and toxic CVD precursors with inexpensive, non-toxic alternative deposition methods using readily available functionalization particles, achieving surface functionalization without the high costs and safety concerns of traditional CVD processes
Solution Approach 2:
The invention converts the potential harm of toxic CVD precursors into a benefit by using safe, non-toxic deposition methods that achieve the same surface functionalization effect while eliminating health and environmental risks
4Adaptability or versatility
If simple mixing of powders is used to combine different materials, then multi-material composition can be achieved, but homogeneity and reproducibility are poor
Solution Approach 1:
The invention performs preliminary action by pre-functionalizing the support particle surfaces with functionalization particles before the additive manufacturing process, ensuring homogeneous and reproducible multi-material composition is locked into each individual grain rather than relying on statistical mixing
Solution Approach 2:
The invention applies local quality by creating functionalization envelopes on specific support particles that provide controlled, homogeneous composition at the grain level, with each particle having its own functionalized surface layer rather than relying on bulk mixing
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 results in improved homogeneity, reproducibility, and microstructural quality of the powders, facilitating additive manufacturing and surface treatment processes by enhancing sintering and densification, while minimizing health risks associated with nanoparticle toxicity.
Implementation Method 1
introduction, into a recirculating fluidized bed reactor, of the support particles in order to stir them by pneumatic and/or hydraulic or mechanical means
Implementation Method 2
the atomization and drying of a suspension composed of powders, a solvent and an organic binder
Implementation Method 3
the atomization and drying of a suspension composed of powders, a solvent and an organic binder
Implementation Method 4
a step of heat treatment of the functionalized particles by raising and maintaining the temperature in the fluidized bed reactor
Data Source
Figure 1
Figure 2
Figure 3A~4B
AI summary
The present invention relates to a multi-material powder comprising support particles with a median particle size (d50) ranging from 1 µm to 100 µm and functionalizing particles having a median particle size (d50) 10 to 1000 times smaller than that of the support particles. According to the invention, the support particles and the functionalizing particles form composite grains with a core-shell structure, each having a core consisting of a support particle and a shell covering between 10 and 100% of the surface of the support particle and formed by at least one surface layer of the functionalizing particles. The present invention also relates to a method for producing such a powder.