Contour-Based Hatch Patterns for Crack-Resistant Additive Manufacturing
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Solution Overview
Problem
Additive manufacturing (AM) techniques, such as direct metal laser melting (DMLM), face challenges in minimizing microcrack formation in fabricated parts, particularly in thin or narrow regions, due to conventional fixed-angle laser hatch lines that do not account for the geometry of the part, leading to reduced quality.
Innovation Solution
The method involves generating contour-based hatching patterns for each build layer of a part, where hatches are defined relative to the part's skeleton, adjusting angles to match the contours, and incorporating spline smoothing and inter-layer hatch angle rotation to minimize crack formation and ensure even spacing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fixed-angle laser hatch lines are used across the part surface, then the manufacturing process is simple and fast, but the risk of microcrack formation increases in thin or narrow regions
Solution Approach 1:
The patent applies dynamics by making the hatch line angles variable rather than fixed. The system dynamically adjusts the angle of laser hatch lines based on the local geometry of the part, specifically adapting to different contour angles and bends. This allows the manufacturing process to respond to varying geometric conditions, reducing crack risk in thin or narrow regions while maintaining efficient manufacturing overall.
Solution Approach 2:
The patent implements local quality by applying different hatch line angles to different regions of the part based on their specific geometric characteristics. Instead of using a uniform angle across the entire part surface, the system tailors the hatching parameters to local contour features, ensuring optimal crack prevention in critical areas like thin or narrow regions while maintaining productivity in other areas.
2Device complexity
If laser hatch lines are generated at fixed angles across the part surface, then the hatching generation is computationally simple, but the quality and accuracy of the fabricated part deteriorates due to increased crack formation
Solution Approach 1:
The system dynamically calculates and adjusts hatch line angles based on the part's geometric features. The computational process determines optimal angles by analyzing local contour characteristics, enabling the system to adapt hatching parameters to each region's specific geometry. This dynamic approach increases computational complexity but significantly improves part quality by reducing crack formation.
Solution Approach 2:
The patent replaces the simple fixed-angle mechanical hatching approach with a computational geometry-based system. Instead of using predetermined fixed angles, the system uses algorithms to calculate optimal hatch angles based on the part's digital model and local geometric features. This substitution of computational methods for mechanical simplicity enables precise control over hatching parameters to improve part quality.
Data Source
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AI summary
A system and method including receiving a data model representation of a part, the data model representation including at least one layer of the part and inner and outer contours for the at least one layer; determining a hatch pattern for each layer of the at least one layer of the part, the hatch pattern for each layer being dependent on the inner and outer contours for each respective layer; generating a record of the determined hatch pattern for each layer, the record including locations for the hatch pattern for each layer; and saving the record of the determined hatch pattern for each layer of the part. In some aspects, the record of the determined hatch pattern for each layer of the part may be used in an additive manufacturing process.