2219-T351 Aluminum vs. 2219-T851 Aluminum
If better ductility is needed, 2219 T351 might be a better choice. However, when higher strength and fatigue resistance are required, 2219 T851 is more suitable.
- 2219-T351: Offers better ductility, suitable for applications requiring higher plasticity and toughness.
- 2219-T851: Has higher overall strength, especially in terms of fatigue strength, shear strength, and tensile strength, making it suitable for high-strength structural components.
2219 aluminum alloy is a high-strength heat-treated aluminum alloy, widely used in the aerospace field, including structural components for rockets, spacecraft, and airplanes. This alloy has excellent strength and high-temperature resistance. T351 and T851 are two common variants, and although they share the same basic alloy composition, they differ in mechanical properties due to different heat treatment processes.
While 2219-T351 aluminum alloy offers a good balance between strength and ductility, 2219-T851 aluminum alloy, with its higher strength, fatigue resistance, and shear strength, performs better in high-load, high-performance applications. The choice between the two should be made based on the specific requirements of the application, particularly in conditions involving high stress or repeated loading, where T851 is undoubtedly the more suitable option.
Differences Between 2219-T351 Aluminum and 2219-T851 Aluminum
| Performance Indicator | 2219-T351 | 2219-T851 | Description |
| Fracture Elongation | Higher | Lower | 2219-T351 has better ductility |
| Fatigue Strength | Lower | Slightly higher | 2219-T851 has slightly higher fatigue strength |
| Shear Strength | Lower | Significantly higher | 2219-T851 has superior shear strength |
| Tensile Strength | Lower | Higher | 2219-T851 has higher ultimate tensile strength and yield tensile strength |
These differences arise from the different heat treatment processes applied to the two variants (T351 vs. T851). The T851 variant is typically subjected to a more stringent aging process to enhance its strength performance.
2219-T351 Aluminum vs. 2219-T851 Aluminum Mechanical Properties
| Property | 2219-T351 Aluminum | 2219-T851 Aluminum |
| Elastic (Young's, Tensile) Modulus, GPa | 72 | 72 |
| Elongation at Break, % | 13 | 7.8 |
| Fatigue Strength, MPa | 98 | 110 |
| Poisson's Ratio | 0.33 | 0.33 |
| Shear Modulus, GPa | 27 | 27 |
| Shear Strength, MPa | 210 | 270 |
| Tensile Strength: Ultimate (UTS), MPa | 340 | 460 |
| Tensile Strength: Yield (Proof), MPa | 230 | 340 |
2219-T351 Aluminum and 2219-T851 Aluminum Heat Treatment Process
- T351: In this condition, the aluminum alloy is first solution heat-treated, followed by cold working, and finally aged. T351 provides a good balance between strength and ductility, making it suitable for applications requiring a compromise between these two properties.
- T851: T851 undergoes a more rigorous heat treatment process, including solution heat treatment, high-temperature aging, and final stress-relieving treatments to reduce residual stress and enhance the material's mechanical properties.
2219-T351 Aluminum and 2219-T851 Aluminum Applications
- 2219-T351 Aluminum Alloy: Due to its good balance of strength and ductility, T351 is commonly used in applications that require moderate strength and some degree of ductility. For example, certain structural components of aircraft and spacecraft, especially those subjected to relatively low stress or requiring some formability, such as frames, panels, and pipelines.
- 2219-T851 Aluminum Alloy: Due to its exceptional strength properties, T851 is suitable for critical applications requiring high strength and performance. These applications include high-stress aerospace components, such as engine parts, rocket nozzles, and structural components subjected to high loads. T851's higher tensile strength, shear strength, and fatigue resistance make it perform better in high-stress environments.
