Powder Removal Systems for Additive Manufacturing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current powder removal methods in additive manufacturing, such as vacuum cleaning and vibrational removal, are inadequate for completely clearing loose powder from complex internal geometries in Powder Bed Fusion (PBF) parts, potentially leading to undesirable sintering or exposure of sensitive mechanics.
Innovation Solution
Placing additively manufactured articles in a non-reactive liquid, like liquid nitrogen, to thermally contract and liberate remaining powder, combined with vibratory forces to dislodge powder from internal channels, utilizing a thermal container and agitators to enhance bubble creation and powder removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional powder removal methods (vacuum cleaning, air gun) are used, then gross powder removal is achieved, but powder remains entrapped in complex internal channels
Solution Approach 1:
The patent introduces an intermediary substance (liquid nitrogen or other non-reactive liquids) to facilitate powder removal from internal channels. The liquid penetrates into the complex geometry and dislodges entrapped powder through boiling, agitation, or thermal contraction effects, achieving complete removal without requiring complex mechanical access to internal passages.
Solution Approach 2:
The patent replaces conventional mechanical powder removal methods (vacuum cleaning, air blasting, vibrational removal) with a chemical/thermal approach using non-reactive liquids. This substitution allows the liquid to flow into and interact with powder in complex internal channels where mechanical methods cannot reach, thereby achieving complete powder removal.
2Manufacturing precision
If chemical removal methods are used, then powder is removed from internal channels, but material integrity may be compromised
Solution Approach 1:
The patent employs chemically inert or non-reactive liquids (such as liquid nitrogen, carbon dioxide, or perfluorinated compounds) that do not react with the metal powder or the additively manufactured part material. This inertness ensures complete powder removal while preserving material integrity, as the liquid does not cause corrosion, chemical reactions, or material degradation.
Solution Approach 2:
The patent utilizes parameter changes in the non-reactive liquid (temperature, phase state, agitation intensity) to control powder removal. For example, liquid nitrogen is introduced at cryogenic temperatures to thermally contract and dislodge powder, then allowed to boil and evaporate, leaving no residual contamination. The parameters are carefully controlled to achieve removal without compromising material properties.
3Manufacturing precision
If vibrational removal is used, then some powder is dislodged, but effectiveness depends on part geometry and vibration distribution
Solution Approach 1:
The patent employs hydraulic principles by using liquid nitrogen or other non-reactive liquids that can flow into and fill complex internal channels of any geometry. The liquid's ability to conform to and penetrate any shape ensures effective powder removal regardless of part geometry, overcoming the limitations of vibrational methods that depend on vibration distribution through the part structure.
Solution Approach 2:
The patent utilizes phase transitions of the non-reactive liquid (particularly liquid nitrogen transitioning from liquid to gas) to enhance powder removal. The boiling and expansion during phase change create agitation and pressure changes that dislodge and expel entrapped powder from internal channels, providing a versatile mechanism that works across different part geometries without relying on vibration distribution.
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 effectively removes powder from complex internal channels without compromising material integrity, ensuring thorough powder removal and preventing sintering, thus improving the efficiency of additive manufacturing processes.
Implementation Method 1
thermally contracting a blockage formed by the remainder powder relative to the one or more internal channels of the additively manufactured article to remove the blockage
Implementation Method 2
allowing the non-reactive liquid to boil to liberate the remainder powder
Implementation Method 3
applying a vibratory force to the non-reactive liquid while the additively manufactured article is within the non-reactive liquid to vibrate the remainder powder within the one or more internal channels
Data Source
AI summary
A method includes placing an additively manufactured article having one or more internal channels in a non-reactive liquid to remove remainder powder from within the one or more internal channels, wherein the non-reactive liquid is a gas at room temperature and/or pressure. Placing the additively manufactured article in the non-reactive liquid includes can include placing the additively manufactured article in liquid nitrogen.