Heated DED Base for Crack and Distortion Control
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Solution Overview
Problem
Direct energy deposition (DED) processes face issues with rapid material expansion and contraction leading to stress-induced cracks and distortion due to rapid heating and cooling, which affect the weldability and quality of the final product.
Innovation Solution
Conductive heating of the base during the DED process to maintain a temperature 100 to 200 degrees Celsius above ambient temperature, reducing the temperature difference between the base and the applied material, thereby controlling stress and improving weldability and reducing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rapid heating and cooling is used in DED process, then deposition speed is improved, but stress-induced cracks and distortion occur
Solution Approach 1:
The base is preheated to a temperature of 100-200°C above ambient temperature before material deposition begins. This preliminary heating action reduces the thermal shock when hot material contacts the base, preventing rapid thermal contraction and subsequent cracking while maintaining efficient deposition rates
Solution Approach 2:
The patent changes the temperature parameter of the base from ambient temperature to elevated temperature (100-200°C above ambient). This parameter change creates a more favorable thermal environment for deposition, reducing thermal gradients and stress accumulation that lead to cracks and distortion
2Productivity
If rapid heating and cooling is used in DED process, then deposition speed is improved, but distortion of desired geometry occurs
Solution Approach 1:
Preheating the base before deposition reduces the thermal gradient between deposited material and substrate. This preliminary action prevents excessive thermal expansion and contraction cycles that would otherwise cause geometric distortion, ensuring dimensional accuracy is maintained during rapid deposition
Solution Approach 2:
By changing the base temperature parameter to 100-200°C above ambient, the patent creates more uniform thermal conditions during deposition. This reduces differential expansion and contraction, thereby minimizing distortion and maintaining geometric fidelity even at high deposition rates
3Ease of manufacture
If base is heated to high temperature, then weldability is improved, but energy consumption increases
Solution Approach 1:
The patent optimizes the heating temperature parameter to a specific range (100-200°C above ambient) that provides sufficient thermal energy to improve weldability and reduce thermal shock, while avoiding excessive energy consumption associated with higher temperatures. This balanced parameter setting achieves good weldability with moderate energy input
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 enhances the strength and quality of the final product by minimizing stress and distortion, resulting in more desirable properties and improved additive manufacturing outcomes.
Implementation Method 1
Conductive heating of the base during the DED process to maintain a temperature 100 to 200 degrees Celsius above ambient temperature
Implementation Method 2
an energy source configured to selectively direct an energized beam at the material to fuse a new layer of the material to a previously formed layer
Data Source
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AI summary
A system used to additively manufacture an object layer-by-layer using direct energy deposition (DED) includes a base (12) where the object is formed, a depositor (14) configured to deposit material layer-by-layer on the base or a previously deposited layer of the object, an energy source (16) configured to selectively direct an energized beam (18) at the material to fuse a new layer of the material to a previously formed layer, and a heating element (20) in contact with at least a portion of the base and configured to supply heat to the base.