Split Wiper Powder Recoating Around Protrusions in Powder Bed Repair
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Powder bed fusion processes like selective laser melting (SLM) and selective laser sintering (SLS) are limited in repairing components with protrusions above the powder bed, as traditional wipers cannot translate across the bed due to obstacles, restricting the repair of complex-shaped components such as turbine blades with damaged platforms.
Innovation Solution
A split wiper system with two segments, each following a different contour of the protruding portion, is used to distribute powder and direct a laser beam to fuse new layers onto the component, allowing for repair by submerging the component partially into the powder bed and using a split wiper with a first and second wiper segment to advance powder and level it across the surface, with optional auger assistance for powder delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a traditional single wiper is used to distribute powder across the powder bed, then the powder distribution is effective for flat surfaces, but the wiper cannot translate across the bed when components with protrusions are present
Solution Approach 1:
The wiper is divided into multiple segments (first wiper segment and second wiper segment) that can independently follow different contours of the component. This segmentation allows each wiper segment to adapt to the specific geometry of the component, enabling the system to handle protrusions and complex shapes that a single rigid wiper cannot accommodate.
2Ease of manufacture
If the component is fully submerged in the powder bed for repair, then the repair area can be accessed, but protruding portions above the powder bed prevent the wiper from sweeping across the bed
Solution Approach 1:
The wiper segments are designed to dynamically adjust their position and contour following capability during translation. This dynamic adaptation allows the wiper to maintain contact with the powder bed surface while navigating around protruding portions of the component, eliminating the need to fully submerge the component or modify the component geometry.
3Adaptability or versatility
If the wiper follows a single contour path, then the wiper structure is simple, but it cannot accommodate complex-shaped components with multiple surface elevations
Solution Approach 1:
The wiper is divided into multiple segments (first wiper segment and second wiper segment) that can independently follow different contours of the component. This segmentation allows each wiper segment to adapt to the specific geometry of the component, enabling the system to handle protrusions and complex shapes that a single rigid wiper cannot accommodate.
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 repair of complex-shaped components with protrusions above the powder bed by effectively distributing and fusing powder, allowing for precise layer formation and repair of components with intricate details, overcoming the limitations of traditional wiper systems.
Implementation Method 1
laser melting/laser sintering of each layer
Implementation Method 2
directing a laser beam across the surface of the powder bed to fuse powder particles
Implementation Method 3
wipers used in SLM and SLS are elements that extend across the powder bed and move in a linear (X-Y axis) fashion to distribute and to level a new layer of powder
Data Source
AI summary
A method of repairing a component using an additive manufacturing process is presented. The method includes submerging the component into a powder bed so that a portion of the component to be repaired is level with a surface of the powder bed and a protruding portion of the component protrudes above the surface of the powder bed, positioning a split wiper that includes a first wiper segment and a second wiper segment in the powder bed at the surface, advancing a quantity of powder by translating the first wiper segment and the second wiper segment across the surface of the powder bed, and directing a laser beam across the surface to fuse powder particles of the powder bed to the underlying substrate forming a layer of the component. Each of the first wiper segment and the second wiper segment follow a different contour of the protruding portion at the surface.