Additive Manufacturing of Al-Fe-Mo Powders for High-Temperature Strength
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Solution Overview
Problem
Additive manufacturing of metal parts, such as selective laser melting (SLM) and direct metal laser sintering (DMLS), requires post-processing techniques that increase time and expense and can reduce mechanical properties, and fail to retain non-equilibrium phases in the microstructure.
Innovation Solution
The method involves melting and rapidly solidifying pre-alloyed powders, like Al—Fe—Mo, using a laser melting technique to form parts with a microstructure containing non-equilibrium phases, which are retained even after finishing, resulting in a near-net shaped part with a dendrite arm spacing of less than 1.0 μm and enhanced mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If post-processing techniques are used to improve density, then manufacturing precision is improved, but loss of time increases and manufacturing cost increases
Solution Approach 1:
The invention performs preliminary consolidation action during the additive manufacturing process itself by controlling layer bonding parameters to achieve near-net-shape density, eliminating the need for subsequent post-processing consolidation steps. This preliminary action prevents the formation of excessive porosity rather than attempting to correct it afterward.
Solution Approach 2:
The invention extracts or removes the post-processing consolidation step from the manufacturing workflow by achieving sufficient density during the additive manufacturing process itself. This extraction eliminates the time and cost associated with separate post-processing operations while maintaining the required manufacturing precision.
2Manufacturing precision
If post-processing techniques are used to improve density, then manufacturing precision is improved, but strength deteriorates
Solution Approach 1:
The invention achieves the desired density and microstructure during the additive manufacturing process itself through controlled layer consolidation, preventing the formation of harmful microstructures that would require post-processing correction. This preliminary action preserves mechanical properties by avoiding subsequent thermal or mechanical treatments that could degrade the material.
3Productivity
If conventional additive manufacturing is used, then productivity is improved, but manufacturing precision deteriorates due to porosity
Solution Approach 1:
The invention changes the parameters of the additive manufacturing process, specifically controlling layer thickness, laser power, and scan speed to optimize layer consolidation. These parameter changes enable the process to achieve near-net-shape density without sacrificing manufacturing speed, as the optimized parameters allow for faster deposition while maintaining adequate bonding.
4Manufacturing precision
If finishing operations are performed on near-net shaped parts, then manufacturing precision is improved, but strength deteriorates due to loss of non-equilibrium phases
Solution Approach 1:
The invention achieves the desired surface finish and dimensional precision during the additive manufacturing process itself through controlled layer deposition and consolidation. This preliminary achievement of precision eliminates or minimizes the need for subsequent finishing operations that would expose the material to thermal cycles capable of transforming beneficial non-equilibrium phases.
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 ultimate tensile strength of the metal parts to greater than 300 MPa at 300°C and 350°C, maintaining high strength and ductility while avoiding the need for costly post-processing techniques.
Implementation Method 1
melting, rapidly solidifying and consolidating pre-alloyed powders via an additive manufacturing process
Implementation Method 2
Both SLM and DMLS processes use a laser to melt successive layers of metal powder
Implementation Method 3
use a laser to melt successive layers of metal powder that solidify into solid metal layers
Data Source
AI summary
A method of manufacturing a part includes melting, rapidly solidifying and consolidating pre-alloyed powders using an additive manufacturing process. The method provides a finished part with a microstructure with at least one non-equilibrium phase. The pre-alloyed powders can be powders of aluminum alloyed with iron and molybdenum, and the additive manufacturing process forms a near-net shaped part that can be finished with techniques such as machining, polishing and drilling, among others. The additive manufacturing process can be a laser melting technique such as selective laser melting or laser metal deposition and an average dendrite arm spacing of the rapidly solidified and consolidate pre-alloyed powders is less than 1.0 μm. Finished parts formed from the aluminum alloy powders alloyed with iron and molybdenum exhibit enhanced strength at elevated temperatures such as an ultimate tensile strength greater than 400 MPa at 300° C. and greater than 350 MPa at 350° C.