Short answer
When designing parts for additive manufacturing that require subsequent machining, carefully control the AM process parameters to minimize porosity, as higher porosity levels will negatively impact tool life and surface finish.
- Field
- Final Production
- Source
- Materials (2020)
- Method
- Experimental investigation and comparative analysis.
- Evidence
- Strong effect
The presence and size of spherical porosity in Inconel 718 produced via laser powder bed fusion directly influence the ease and quality of subsequent machining operations. This final production research insight is drawn from a 2020 study published in Materials. Using Experimental investigation and comparative analysis., researchers explored how this design variable affects real-world outcomes. The key design takeaway: When designing parts for additive manufacturing that require subsequent machining, carefully control the AM process parameters to minimize porosity, as higher porosity levels will negatively impact tool life and surface finish.
Porosity in Additively Manufactured Inconel 718 Significantly Impacts Machining Performance
The presence and size of spherical porosity in Inconel 718 produced via laser powder bed fusion directly influence the ease and quality of subsequent machining operations.
Materials · 2020
Key Findings
- 01Higher porosity levels in AM Inconel 718 led to a greater tendency for built-up-edge (BUE) formation on the cutting tool.
- 02Machining performance, particularly in terms of tool wear and surface finish, is significantly influenced by the porosity characteristics of the AM material.
- 03Wrought Inconel 718 exhibited different machining behavior compared to the AM samples, likely due to its dense, homogeneous microstructure.
Application
Design takeaway
When designing parts for additive manufacturing that require subsequent machining, carefully control the AM process parameters to minimize porosity, as higher porosity levels will negatively impact tool life and surface finish.
How to apply
When specifying AM parameters for Inconel 718 components requiring machining, prioritize settings that yield a dense, low-porosity microstructure. If higher porosity is unavoidable, anticipate increased tool wear and potential surface finish issues, and adjust machining parameters or consider alternative finishing methods.
Project actions
- 01When selecting materials for your design project, research how their manufacturing method affects their properties.
- 02Consider the entire lifecycle of your product, including any finishing or assembly steps.
Method & Evidence
Variables
Strengths & Limitations
Strengths
- +Direct comparison between AM and wrought material.
- +Instrumented machining tests providing quantitative force data.
Limitations
The study was limited to specific machining conditions and one alloy; results may not apply to all AM materials or all machining scenarios.
Reliability & validity
The use of a dynamometer for force measurement and controlled experimental conditions contributes to the reliability and validity of the findings regarding cutting forces. Visual observation of BUE and tool wear, while potentially subjective, is a standard method for assessing machinability.
Think critically
How might the type and distribution of porosity (e.g., spherical vs. irregular, clustered vs. uniform) further influence machinability beyond what was observed in this study?
Design Principles
"Material microstructure, influenced by manufacturing processes, directly dictates its performance in subsequent operations."
Additive manufacturing (AM) offers near-net-shape capabilities, but achieving tight tolerances and smooth finishes often necessitates machining. Understanding how AM process parameters, specifically those affecting microstructure like porosity, impact machinability is crucial for predicting and optimizing post-processing steps, ensuring final product quality and performance.
What This Means for Your Design
If you 3D print metal parts that need to be machined later, the tiny holes (porosity) inside the metal can make the machining process harder and messier.
How to use in your project
- 1.Reference this study when discussing the challenges of post-processing additively manufactured components, particularly concerning material properties and machining.
Add to My Project
Quick Cite
Paragraph starter
This research highlights that the internal microstructure of additively manufactured materials, specifically the level of spherical porosity in Inconel 718, has a significant impact on its machinability. Higher porosity levels were found to promote built-up-edge formation on cutting tools, indicating a more challenging machining process and potential degradation of surface finish and tool life, which is a critical consideration for components requiring precise post-processing.
Source
Materials
Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities
journal · 2020
View sourceQuestions About This Research
- What does the research say about porosity in additively manufactured inconel 718 significantly impacts machining performance?
- When designing parts for additive manufacturing that require subsequent machining, carefully control the AM process parameters to minimize porosity, as higher porosity levels will negatively impact tool life and surface finish. Evidence: Materials (2020).
- Why does "Porosity in Additively Manufactured Inconel 718 Significantly Impacts Machining Performance" matter for design?
- Additive manufacturing (AM) offers near-net-shape capabilities, but achieving tight tolerances and smooth finishes often necessitates machining. Understanding how AM process parameters, specifically those affecting microstructure like porosity, impact machinability is crucial for predicting and optimizing post-processing steps, ensuring final product quality and performance.
- How can designers apply this research?
- When designing parts for additive manufacturing that require subsequent machining, carefully control the AM process parameters to minimize porosity, as higher porosity levels will negatively impact tool life and surface finish.
- What were the main findings?
- Higher porosity levels in AM Inconel 718 led to a greater tendency for built-up-edge (BUE) formation on the cutting tool.. Machining performance, particularly in terms of tool wear and surface finish, is significantly influenced by the porosity characteristics of the AM material.. Wrought Inconel 718 exhibited different machining behavior compared to the AM samples, likely due to its dense, homogeneous microstructure.
- What research method was used?
- Experimental investigation and comparative analysis..
- How strong is the evidence?
- Evidence strength is rated Strong effect, based on a 2020 journal from Materials.
- What should I do differently in my next project?
- When specifying AM parameters for Inconel 718 components requiring machining, prioritize settings that yield a dense, low-porosity microstructure. If higher porosity is unavoidable, anticipate increased tool wear and potential surface finish issues, and adjust machining parameters or consider alternative finishing methods.
- What are the limitations?
- The study focused on light cutting conditions and dry machining; performance under heavy cuts or with lubrication might differ. Tool wear was limited to short durations, so long-term wear characteristics were not fully explored.