3D Printing Metal Powder Flow Additive for Sintering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 3D printing technologies face challenges in using small particle metal powders due to their poor flowability and cohesive nature, which affects the spreadability and mechanical properties of final metal objects, especially when using sintering processes, as traditional flow additives like fumed silica and alumina can compromise structural integrity.
Innovation Solution
A build material composition comprising a host metal with a flow additive that is reducible to an elemental metal in a reducing environment, allowing for improved spreadability and incorporation into the bulk metal phase without detrimental effects on mechanical properties, using a thermally decomposing precursor that forms elemental metal during the sintering process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If small particle metal powders are used in 3D printing, then the mechanical properties and surface finish of final metal objects are improved, but the flowability and spreadability of the powder deteriorates
Solution Approach 1:
The patent introduces a flow additive as an intermediary substance that mediates between the small particle metal powder and the processing environment. The flow additive coats the metal powder particles, reducing interparticle friction and improving flowability without altering the fundamental mechanical properties of the metal itself. This allows small particle powders to be processed effectively while maintaining their superior mechanical characteristics.
Solution Approach 2:
The patent modifies the surface characteristics of metal powder particles by adding flow additives, which changes parameters such as surface roughness, interparticle friction, and flow dynamics. This parameter change enables small particle powders to achieve adequate flowability for 3D printing processes while retaining their fine particle size and associated mechanical benefits.
2Ease of operation
If traditional flow additives like fumed silica and alumina are used, then the flowability of metal powder is improved, but the structural integrity and mechanical properties of final metal objects deteriorate
Solution Approach 1:
The patent employs organic flow additives that serve their purpose during the 3D printing process and then decompose or burn off during subsequent heat treatment. These temporary flow additives improve powder flowability during printing but are designed to be consumed or removed in later processing stages, leaving no harmful residues that would compromise the structural integrity of the final metal object.
Solution Approach 2:
The patent utilizes phase transitions of organic flow additives, which transition from solid or liquid state during printing to gas state during heat treatment. This phase change allows the flow additive to perform its function during printing and then disappear during subsequent processing, avoiding any negative impact on the mechanical properties of the final metal object.
3Quantity of substance
If small particle metal powders are used, then the density and surface finish of final metal objects are improved, but the cohesive nature of the powder worsens the spreadability
Solution Approach 1:
The flow additive acts as an intermediary that reduces cohesive forces between small particle metal powders. By coating the particles and reducing interparticle attraction, the flow additive enables small particle powders to be spread effectively while maintaining their high density and fine surface finish characteristics.
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
Enables the use of small particle metal powders with improved flowability and mechanical properties comparable to those produced without flow additives, maintaining strength and ductility while allowing for the recovery of used metal powders in Selective Laser Melting processes.
Implementation Method 1
a flow additive present in an amount ranging from about 0.01 weight percent to about 5.00 weight percent, based on the total weight of the composition, wherein the flow additive consists of a metal containing compound that is reducible to an elemental metal in a reducing environment at a reducing temperature less than a sintering temperature of the host metal
Implementation Method 2
using a thermally decomposing precursor that forms elemental metal during the sintering process
Implementation Method 3
at a reducing temperature less than a sintering temperature of the host metal, wherein the elemental metal is capable of being incorporated into a bulk metal phase of the host metal in a final metal object
Data Source
Figure 1~2A
Figure 2B~2C
Figure 3~4
AI summary
An example of a composition includes a host metal present in an amount ranging from about 95.00 weight percent to about 99.99 weight percent, based on a total weight of the composition. A flow additive is present in an amount ranging from about 0.01 weight percent to about 5.00 weight percent, based on the total weight of the composition. The flow additive consists of a metal containing compound that is reducible to an elemental metal in a reducing environment at a reducing temperature less than or equal to a sintering temperature of the host metal. The elemental metal is capable of being incorporated into a bulk metal phase of the host metal in a final metal object. The composition is spreadable, having a Hausner Ratio less than 1.25.