Multi-Energy Meltpool Control for Additive Manufacturing Bead Precision
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Solution Overview
Problem
Existing additive manufacturing (AM) processes lack independent control over bead shape, deposition rate of feedstock material, and overall process temperature, leading to inflexibility and potential fusion defects in producing near net-shape 3D articles.
Innovation Solution
Decoupling the roles of multiple energy sources, such as a plasma transferred arc and lasers, allows independent control of meltpool initiation, growth, and feedstock melting, enabling precise adjustment of bead width, deposition rate, and process temperature to produce high-quality 3D articles at faster build rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single energy source is used to form and control the meltpool, then the device complexity is reduced, but the manufacturing precision deteriorates because bead shape parameters (single bead width, contact angle, layer height) cannot be independently controlled
Solution Approach 1:
The single energy source is segmented into multiple energy sources (first energy source and second energy source), each performing distinct functions: the first energy source initiates the meltpool while the second energy source controls the bead shape parameters. This segmentation enables independent control of meltpool formation and bead geometry, resolving the contradiction between device simplicity and manufacturing precision.
2Productivity
If the energy source power is increased to improve layer height and build rate, then the productivity is improved, but the manufacturing precision deteriorates due to loss of independent control over bead shape parameters
Solution Approach 1:
By segmenting the energy source into two independent sources, the system can increase total power input for higher build rates while maintaining independent control over bead shape parameters. The first energy source provides the necessary power for rapid melting and deposition, while the second energy source independently adjusts bead geometry to maintain manufacturing precision.
Solution Approach 2:
The system changes the parameter of energy source configuration from single to multiple sources, enabling simultaneous optimization of power input (for productivity) and energy distribution control (for precision). Each energy source can be independently tuned to achieve optimal bead shape parameters at various build rates.
3Productivity
If the feed rate of feedstock is increased to improve deposition rate, then the productivity is improved, but the manufacturing precision deteriorates due to potential lack of fusion defects
Solution Approach 1:
The segmented energy source configuration allows the first energy source to handle high feed rate melting requirements while the second energy source ensures adequate thermal energy distribution for complete fusion. This separation of functions enables high deposition rates without sacrificing fusion quality, as each energy source can be independently optimized for its specific role.
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
Achieves improved net-shaping of 3D articles with controlled resolution and microstructure, while maintaining efficient melting and uniform deposition, thereby enhancing production speed and quality.
Implementation Method 1
a first energy source to impinge the substrate or previously deposited layers to initiate a meltpool
Implementation Method 2
a second energy source to direct energy onto the substrate or previously deposited layers to grow the meltpool width to a desired size
Implementation Method 3
an energy source such as a plasma arc, an electron beam or a laser is used to form the meltpool. This energy source can also be used to provide the energy to melt the feedstock as it enters the meltpool and to govern the overall temperature of the process (and therefore govern the cooling conditions and the microstructure and mechanical properties of the 3D article)
Data Source
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AI summary
A method of producing a 3D article by additive manufacture is provided. The method includes the steps of: forming a meltpool in an already-existing part of the article, and moving the meltpool relative thereto; feeding a directed feedstock into the moving meltpool to deposit and fuse a layer of material on the already-existing part; and repeating the forming and moving and feeding steps to build up successive layers of material. In performance of the forming and moving step: a first energy source impinges at a first region of the already-existing part which moves with and leads the meltpool, whereby the first energy source initiates the formation of the meltpool; and a second energy source impinges at a second region on the already-existing part which moves with and follows the first region, whereby the second energy source grows the lateral width of the meltpool before the feedstock is fed therein.