Metallic Microlayer Sealing for 3D-Printed Microfeature Densification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Additively-manufactured high-temperature components with microfeatures often exhibit surface porosity, which affects their performance and makes them unsuitable for hot isostatic pressing, and conventional infiltration methods can degrade the material properties, making them unsuitable for high-temperature applications.
Innovation Solution
A process involving additive manufacturing of components with microfeatures, followed by coating the external and internal surfaces with a metallic microlayer to seal porosity and subsequent densification using hot isostatic pressing to achieve full density and superior mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional infiltration by low-melting point alloy is used to address near-surface porosity, then porosity is reduced, but the properties of the 3-D printed parent alloy are degraded
Solution Approach 1:
A metallic microlayer is introduced as an intermediary substance that seals surface porosity without degrading the parent alloy properties. This microlayer acts as a mediator that fills and seals pores while maintaining the mechanical properties of the underlying 3-D printed alloy, avoiding the harmful effects of conventional low-melting point alloy infiltration.
Solution Approach 2:
The invention changes the physical and chemical parameters of the surface layer by applying a metallic microlayer coating. This coating modifies the surface characteristics to seal porosity while the bulk material parameters remain unchanged, preserving the high-temperature strength and other critical properties of the parent alloy.
2Manufacturing precision
If hot isostatic pressing is attempted on components with surface-connected porosity, then densification is attempted, but the porosity cannot be sealed and healing is impossible
Solution Approach 1:
The metallic microlayer is applied in advance before hot isostatic pressing to seal all surface-connected porosity. This preliminary sealing action prevents gas escape during subsequent HIPing, enabling successful densification that would otherwise be impossible due to surface-connected pores.
Solution Approach 2:
The microlayer serves as an intermediary barrier that seals surface pores, allowing the HIPing process to effectively densify the component. Without this intermediary sealing layer, the surface-connected porosity would prevent proper densification during hot isostatic pressing.
3Adaptability or versatility
If 3-D printing is used to create components with intricate microfeatures, then design flexibility is improved, but surface porosity increases due to increased surface area and small feature size
Solution Approach 1:
The metallic microlayer is selectively applied to seal surface porosity in regions with intricate microfeatures while leaving the bulk material properties unchanged. This local quality modification addresses the specific problem of high surface porosity in complex geometries without affecting the overall design flexibility or bulk mechanical 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 effectively seals surface porosity, enables hot isostatic pressing of high-temperature components, and maintains superior material properties, enhancing the applicability of 3-D printing for gas turbine components and other high-temperature applications by achieving a combination of high density and good mechanical properties.
Implementation Method 1
coating the surfaces of the formed article, including the surfaces of the microfeature, with a microlayer coating to seal the formed article
Implementation Method 2
densifying the sealed article
Data Source
AI summary
A process includes forming a printed article having an external surface and at least one microfeature with an internal surface by additive manufacture, coating the external surface and the internal surface of the printed article with a metallic microlayer to form a coated article, and densifying the coated article to form a component. After formation, the printed article has a porosity such that the printed article is not at full density. A densified component includes a printed article having an external surface and at least one microfeature with an internal surface and a metallic microlayer coating the external surface and the internal surface of the printed article. The printed article is formed by additive manufacture.