Excess Thickness Setting for Residual-Stress Compensation in AM
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Solution Overview
Problem
In additive manufacturing, residual stress generated during thermal shrinkage leads to deformation and errors in the target shape of built objects, necessitating increased manufacturing costs and time due to the need for large cutting allowances, which existing techniques fail to address by adjusting the manufacturing plan accordingly.
Innovation Solution
The method involves predicting thermal shrinkage and release strain deformations to modify the building shape, adjusting the excess metal amount to ensure it falls within a predetermined range, thereby improving accuracy and reducing manufacturing time and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the excess metal amount is increased to prevent shape errors due to residual stress release, then the manufacturing accuracy is improved, but the manufacturing cost and manufacturing time are increased
Solution Approach 1:
The patent applies preliminary action by predicting thermal shrinkage and release strain before machining, then pre-modifying the building shape to compensate for expected deformations. This allows the excess metal amount to be optimized in advance, avoiding both over-cutting and under-cutting, thereby reducing machining time while maintaining shape accuracy.
Solution Approach 2:
The patent changes the parameter of excess metal amount from a fixed large value to a dynamically optimized value based on predicted deformation. By calculating the relationship between building parameters and deformation, the system determines the precise excess metal amount needed, reducing unnecessary material removal and machining time.
2Manufacturing precision
If the excess metal amount is increased to prevent shape errors due to residual stress release, then the manufacturing accuracy is improved, but the manufacturing cost is increased
Solution Approach 1:
The patent optimizes the excess metal amount parameter by establishing a relationship between building parameters and deformation. This allows the system to determine the minimum necessary excess metal amount for each specific case, reducing material waste while ensuring shape accuracy is maintained.
Solution Approach 2:
The patent implements feedback by using predicted deformation information to adjust the building plan. The system calculates expected thermal shrinkage and release strain, then feeds this information back into the building shape design to optimize excess metal distribution, minimizing unnecessary material removal.
3Measurement precision
If the existing techniques predict deformation but do not adjust the manufacturing plan, then the deformation can be calculated, but the manufacturing cost and time cannot be reduced
Solution Approach 1:
The patent takes preliminary action by not only predicting deformation but also using this prediction to modify the building shape before manufacturing. This closes the loop between prediction and action, allowing the excess metal amount to be optimized based on predicted deformation, thereby improving manufacturing efficiency.
Solution Approach 2:
The patent implements feedback by using deformation prediction results to adjust the building plan. The predicted thermal shrinkage and release strain are fed back into the manufacturing process design, enabling dynamic optimization of excess metal amount and improving overall manufacturing efficiency.
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 accuracy of building and machining while reducing manufacturing costs and time by accurately setting the excess metal amount, considering thermal deformation and release strain, leading to more efficient production processes.
Implementation Method 1
When an arc is used as a heat source, a filler metal is melted and solidified by the arc to form a bead
Implementation Method 2
a filler metal is melted and solidified by the arc
Implementation Method 3
a residual stress is generated inside a built object due to thermal shrinkage
Implementation Method 4
The 3D printer that builds a metal material melts a metal powder or a metal wire using a heat source such as a laser
Implementation Method 5
The 3D printer that builds a metal material melts a metal powder or a metal wire using a heat source such as a laser, an electron beam, or an arc
Data Source
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AI summary
The present invention comprises: a thermal shrinkage prediction step for predicting the amount of post-shaping thermal shrinkage of a laminate; a thermal shrinkage correction step for expanding the target profile of a shaped object in accordance with the amount of thermal shrinkage to obtain a thermal deformation correction profile; a released strain prediction step for predicting the amount of elastic deformation according to post-machining released strain of the laminate; an elastic deformation correction step for deforming the thermal deformation correction profile in accordance with the amount of elastic deformation in a direction opposite the deformation direction according to the released strain to obtain an elastic deformation correction profile; and an excess thickness setting step for adjusting the contour shape of the laminate so that the excess thickness from the elastic deformation correction profile to the contour of the laminate is within a predetermined reference range.