When comparing aluminum 6061-T6 and 6061-T651, there are key mechanical differences that can affect the performance of parts produced through CNC machining or milling:
Aluminum 6061-T6
- Heat Treatment: This alloy is solution heat-treated and artificially aged, which enhances its strength significantly.
- Mechanical Properties:
- Yield Strength: Approximately 276 MPa (40,000 psi)
- Tensile Strength: Approximately 310 MPa (45,000 psi)
- Elongation: Around 10-12% (dependent on thickness)
- Applications: Commonly used in structural applications, aerospace components, and automotive parts due to its high strength-to-weight ratio.
Aluminum 6061-T651
- Heat Treatment: Similar to T6 but with additional stress-relieving processes that reduce residual stresses from machining.
- Mechanical Properties:
- Yield Strength: Similar to T6, around 276 MPa (40,000 psi)
- Tensile Strength: Also similar, about 310 MPa (45,000 psi)
- Elongation: Typically higher than T6, around 12-16%
- Applications: Often used in applications where improved machinability and stress relief are critical, such as in complex geometries or parts that undergo further machining.
Key Differences
- Stress Relief: 6061-T651 has gone through a stress-relieving process, making it less likely to warp or crack during machining than T6.
- Machinability: T651 is often easier to machine due to its lower residual stress, which can result in better surface finishes and dimensional stability.
- Elongation: T651 typically exhibits better elongation, making it more ductile and better suited for applications involving bending or forming.
Conclusion
When choosing between the two for CNC machining, consider the specific mechanical requirements of your prototype, including strength, ductility, and stability during machining. If the parts will undergo further machining or require tight tolerances, 6061-T651 may be the better choice. If maximum strength is the priority, then 6061-T6 could be more suitable.