Friction Stir Weld Tool Grain Structure Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current friction stir welding tools are costly and require complex processes, with materials often exhibiting poor distribution and homogeneity of chemical constituents, leading to suboptimal strength and durability.
Innovation Solution
Development of friction stir weld tools composed of tungsten and rhenium with carbide and oxide dispersoids, featuring grains of 100 nm to 10 micrometers in diameter, fabricated using nanopowder processing techniques that include sintering at lower temperatures and times, allowing for improved distribution and homogeneity of chemical constituents, and enhanced mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional friction stir welding tools are used, then they can perform welding operations, but they are costly and exhibit poor distribution and homogeneity of chemical constituents
Solution Approach 1:
The patent changes the grain size parameter to the nanoscale (100 nm to 10 micrometers) and uses nanopowder processing techniques, which fundamentally alters the manufacturing approach. This enables improved distribution and homogeneity of chemical constituents while using cost-effective fabrication methods with fewer process steps compared to conventional tools.
Solution Approach 2:
The tool comprises a composite microstructure with tungsten and rhenium grains, carbide dispersoids, and oxide dispersoids. This composite structure at the nanoscale achieves superior homogeneity of chemical constituents and material properties while maintaining manufacturability through nanopowder sintering processes.
2Strength
If grain size is reduced to improve material properties, then hardness and strength increase, but manufacturing complexity increases
Solution Approach 1:
The patent uses pre-synthesized nanopowders with controlled grain sizes (100 nm to 10 micrometers) as the starting material. This preliminary preparation of nanoscale powders enables the final sintering process to produce tools with fine grain structures and high hardness without requiring complex post-processing steps to achieve the desired grain size.
Solution Approach 2:
By changing the sintering parameters (temperature and time) and using nanopowder inputs, the process achieves fine grain structures (100 nm to 10 micrometers) that result in high hardness (at least 450 HV) while keeping the fabrication process relatively simple and cost-effective.
3Reliability
If rhenium content is increased to improve material properties, then strength and durability improve, but manufacturing cost increases
Solution Approach 1:
The patent optimizes the rhenium content parameter to less than or equal to 5 wt%, which is sufficient to achieve the desired strength and durability when combined with the fine grain structure (100 nm to 10 micrometers). This optimized composition achieves high reliability while minimizing the quantity of expensive rhenium required.
4Ease of manufacture
If nickel is excluded to simplify composition, then manufacturing cost decreases, but material properties deteriorate
Solution Approach 1:
The patent changes the grain size parameter to nanoscale dimensions (100 nm to 10 micrometers) and uses nanopowder processing, which enables the tool to achieve high strength and durability without requiring nickel. The fine grain structure itself provides the necessary material properties, allowing nickel to be excluded for cost reduction.
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 resulting tools exhibit increased hardness, durability, and cost-effectiveness with improved material properties, such as hardness values of at least 450 HV at room temperature, and reduced grain size, enabling changes in composition that would otherwise result in poor performance.
Implementation Method 1
fabricated using nanopowder processing techniques that include sintering at lower temperatures and times
Implementation Method 2
the friction stir weld tool can have substantially no nickel... exhibit a hardness value of at least 450 HV at room temperature
Data Source
AI summary
Tools for friction stir welding can be made with fewer process steps, lower cost techniques, and/or lower cost ingredients than other state-of-the-art processes by utilizing improved compositions and processes of fabrication. Furthermore, the tools resulting from the improved compositions and processes of fabrication can exhibit better distribution and homogeneity of chemical constituents, greater strength, and/or increased durability. In one example, a friction stir weld tool includes tungsten and rhenium and is characterized by carbide and oxide dispersoids, by carbide particulates, and by grains that comprise a solid solution of the tungsten and rhenium. The grains do not exceed 10 micrometers in diameter.