Cold-Sprayed Build Plate Structure for Warping-Resistant PBF-L
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In laser powder bed fusion additive manufacturing, build plates face tensile stresses and warping due to thermal loading, leading to potential failure and increased costs, especially with large bulky builds, and require material compatibility with the workpiece, often using expensive materials like titanium.
Innovation Solution
A build plate with a support region and a top region formed using a cold spray process to induce compressive stresses, counteracting tensile stresses, and allowing for the reuse of build plates by repairing defects and reapplying a metal layer with compressive stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If build plates are made from expensive materials like titanium to ensure material compatibility and strength, then the reliability and strength of the build plate improve, but the cost increases
Solution Approach 1:
The build plate is divided into two distinct regions: a support region made from cost-effective materials and a top region made from expensive titanium material. This segmentation allows the expensive material to be used only where necessary (the top region that contacts the workpiece) while the support region uses cheaper materials, thus reducing overall cost while maintaining the required strength and compatibility.
Solution Approach 2:
Different regions of the build plate are assigned different material properties. The top region has titanium material properties for compatibility and strength, while the support region has different, more cost-effective material properties. This local differentiation optimizes both cost and performance by applying expensive materials only where absolutely necessary.
2Productivity
If build plates are used for large bulky builds, then productivity is improved, but the build plate experiences warping and tensile failure due to thermal loading
Solution Approach 1:
Compressive stresses are intentionally introduced into the top region of the build plate during its fabrication process. These pre-applied compressive stresses counteract the tensile thermal stresses that develop during laser powder bed fusion operations, preventing warping and tensile failure. This preliminary anti-action allows the build plate to reliably support large bulky builds without deformation or failure.
Solution Approach 2:
The stress state of the build plate is fundamentally changed by introducing compressive stresses into the top region. This parameter change in the stress distribution allows the build plate to withstand the thermal loading conditions of large builds without experiencing the typical warping and tensile failure modes.
3Reliability
If build plates are designed for single use to avoid failure risks, then reliability is maintained, but cost increases due to continuous replacement
Solution Approach 1:
Instead of discarding the entire build plate after a single use, the patent enables recovery and reuse of the support region. When the top region becomes damaged or worn, it can be removed and replaced with a fresh top region while retaining the expensive support region structure. This selective replacement approach maintains reliability while significantly reducing costs by recovering and reusing the majority of the build plate.
Solution Approach 2:
The build plate is segmented into a reusable support region and a replaceable top region. This segmentation allows the support region to be recovered and reused multiple times, while only the top region needs periodic replacement. This approach transforms the build plate from a single-use component to a multi-use component with replaceable parts, reducing overall cost while maintaining reliability.
4Manufacturing precision
If the top region is made thick to provide sufficient material for machining and polishing, then manufacturing precision is improved, but the amount of material required increases
Solution Approach 1:
Rather than making the entire build plate thick to allow for machining and polishing, the patent applies a relatively thin top region (sufficient for the intended number of rebuilds) on top of the support region. This partial application of material provides enough excess material for surface preparation operations without the excessive material consumption that would result from making the whole plate thick.
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
The solution effectively reduces the risk of build plate failure and allows for the reuse of build plates, reducing costs by using less expensive materials for the support region while maintaining compatibility with the workpiece, and improving the durability of build plates during additive manufacturing campaigns.
Implementation Method 1
The top region is formed on the support region by a cold spray process
Implementation Method 2
the top region is polished by a laser in the PBF-L additive manufacturing system
Implementation Method 3
uses a laser to sinter or fuse metallic or polymeric particles together
Implementation Method 4
uses a laser to sinter or fuse metallic or polymeric particles together
Data Source
AI summary
A build plate for a powder bed fusion-laser (PBF-L) additive manufacturing system has a support region and a top region. The top region is formed on the support region by a cold spray process, such that the top region is under a compressive stress. The build plate can be prepared by preparing the build plate support region to receive the top region and depositing, using a cold spray process, a layer of metal on the support region. The layer of metal is formed with a compressive stress to form the top region. The top region is then machined to provide a desired surface roughness.