Powder Spreading Quality Test Method for Additive Manufacturing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing SLM devices lack the capability to test the quality of powder spreading, leading to potential damage and low precision in part formation due to uneven powder distribution.
Innovation Solution
A method involving symmetrically disposed light sources and a photographing apparatus to capture and synthesize images of the powder spreading surface, analyzing gray scale values to detect defects and determine the cause of failure, with a computer-controlled system for re-spreading powder as needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If no testing capability is added to the SLM device, then the device structure remains simple, but the manufacturing precision and reliability of powder spreading cannot be ensured
Solution Approach 1:
The patent replaces manual visual inspection of powder spreading with an automated optical detection system. A camera captures images of the powder layer, and image processing algorithms automatically analyze the spreading quality, substituting mechanical/visual inspection with optical and computational methods to achieve precise measurement without manual intervention
Solution Approach 2:
The patent introduces an intermediary image processing system between the powder spreading process and the evaluation stage. By capturing images through a camera and processing them through algorithms, the system creates an intermediate digital representation that enables precise, automated quality assessment without directly modifying the core spreading mechanism
2Productivity
If manual inspection of powder spreading is performed, then device complexity remains low, but productivity decreases due to time-consuming inspection processes
Solution Approach 1:
The inspection system performs self-service by automatically capturing images and processing them through algorithms without requiring external manual intervention. The system evaluates powder spreading quality autonomously, eliminating the need for operators to manually inspect each layer, thereby significantly improving inspection efficiency
Solution Approach 2:
The patent replaces manual inspection processes with automated optical detection and image processing. The camera and algorithm system automatically evaluates powder spreading quality, substituting time-consuming manual examination with rapid computational analysis that operates without human intervention
3Measurement precision
If symmetric light sources are used to illuminate the powder surface, then measurement precision improves, but device complexity and cost increase
Solution Approach 1:
The patent employs symmetric light sources positioned at symmetric angles (e.g., ±45 degrees) relative to the camera axis, creating an asymmetric illumination pattern that enhances the visibility of surface defects. This symmetric arrangement of light sources produces consistent lighting conditions that improve measurement precision while maintaining structural regularity
Solution Approach 2:
The patent applies localized illumination through strategically positioned light sources that specifically illuminate the powder spreading area. By concentrating lighting only where needed and positioning sources at optimal angles, the system achieves high measurement precision in the critical measurement zone without requiring complex illumination throughout the entire device
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
Ensures precision and improves forming quality by automatically testing and adjusting powder spreading, enhancing the automation and efficiency of the additive manufacturing process.
Implementation Method 1
illuminating... a forming area successively and separately by light sources symmetrically disposed on two sides of the forming area perpendicular to a powder spreading direction
Implementation Method 2
photographing, by a photographing apparatus located above the forming area, a powder spreading surface separately illuminated by each of the light sources
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Disclosed is a method for testing the quality of powder spreading, including: illuminating, after a powder spreading apparatus completes spreading of a single layer of powder, a forming area (3) successively and separately by light sources, and performing, by a photographing apparatus (7), photographing twice, to obtain two images of powder spreading; synthesizing the two images of powder spreading; determining an overall gray scale of the synthesized image, and if the overall gray scale is consistent, the powder spreading being successful, and if not, processing the synthesized image by using a method of gray scale threshold segmentation, and marking an area contained in a contour boundary inside the synthesized image as a suspected defect area; and determining whether the powder spreading is successful according to a gray scale value. Also disclosed is a device for testing the quality of powder spreading, including: light sources symmetrically disposed on two sides of a forming chamber (8) perpendicular to a powder spreading direction, and a photographing apparatus (7) located above a forming area, the light sources and the photographing apparatus (7) all being connected to a computer (9). The present invention realizes a function of testing the quality of powder spreading on an additive manufacturing device, and can spread the powder again when the powder spreading does not satisfy requirements, and meanwhile, it can also automatically analyzes a cause of failure of the powder spreading.