7178-T651 Aluminum vs. 7178-T6510 Aluminum
7178 T651 and 7178-T6510 aluminum alloys are different heat treatment states of the 7178 aluminum alloy, which improve the mechanical properties of the metal through solution heat treatment, stress relief, and artificial aging. Although their manufacturing processes are similar, these two states differ in certain characteristics due to the differences in stress relief and stretching treatments.
- 7178-T651 offers better ductility and fatigue strength, making it suitable for applications that undergo repeated loads and larger deformations, especially for aerospace structural components that require toughness and fatigue resistance.
- 7178-T6510 performs better in ultimate tensile strength, making it suitable for applications that experience higher tensile loads but do not require particularly high ductility, such as certain high-load structural components.
The choice between these two materials primarily depends on the specific application requirements: if the focus is on high fatigue strength and ductility, 7178-T651 is more suitable; if the emphasis is on tensile strength with less emphasis on ductility, 7178-T6510 might be the better choice.
Performance Comparison Table of 7178-T651 and 7178-T6510 Aluminum Alloys
| Performance Index | 7178-T651 Aluminum | 7178-T6510 Aluminum |
| Heat Treatment State | Solution heat treatment + Stress relief + Artificial aging | Solution heat treatment + Stress relief + Artificial aging |
| Stress Relief Method | Stretched to a certain extent, depending on the type of forging (thin plate, plate, rod, forging) | Stretched to a certain extent, depending on the type of forging (extrusions, pipes), not straightened after stretching |
| Ductility (Fracture Elongation) | Higher fracture elongation, better ductility | Lower fracture elongation, poorer ductility |
| Fatigue Strength | Slightly higher, able to withstand more stress cycles | Slightly lower, more prone to fatigue failure |
| Ultimate Tensile Strength | Slightly lower, weaker than T6510 | Slightly higher, with stronger tensile strength |
| Suitable Applications | Suitable for applications requiring high fatigue strength and high stress cycles, such as aerospace and automotive industries | Suitable for applications requiring high strength, but not suitable for high-frequency loads, such as aircraft structural components and other high-strength parts |
| Characteristics | Better ductility and fatigue resistance, suitable for applications requiring high durability | Higher tensile strength, suitable for high-strength loads, but with poorer fatigue strength and ductility |
7178-T651 Aluminum vs. 7178-T6510 Aluminum Mechanical Properties
| Property | 7178-T651 Aluminum | 7178-T6510 Aluminum |
| Elastic (Young's, Tensile) Modulus (GPa) | 71 | 71 |
| Elongation at Break (%) | 8.0 | 4.6 |
| Fatigue Strength (MPa) | 200 | 180 |
| Poisson's Ratio | 0.32 | 0.32 |
| Shear Modulus (GPa) | 27 | 27 |
| Shear Strength (MPa) | 370 | 370 |
| Tensile Strength: Ultimate (UTS) (MPa) | 630 | 640 |
| Tensile Strength: Yield (Proof) (MPa) | 550 | 550 |
Ductility (Fracture Elongation)
7178-T651 has better ductility than 7178-T6510. Ductility refers to the ability of a material to elongate before fracture. The higher fracture elongation of 7178-T651 means it exhibits better deformation capability during stretching, which is crucial for applications requiring higher toughness, such as aerospace structural components.
- 7178-T651: Better ductility, suitable for applications that undergo larger deformations.
- 7178-T6510: Poorer ductility, suitable for applications that require higher strength but smaller deformations.
Fatigue Strength
7178-T651 has higher fatigue strength than 7178-T6510. This means that under repeated loads, 7178-T651 can withstand more stress cycles without experiencing fatigue fracture. Fatigue strength is crucial for applications that endure cyclic loads.
- 7178-T651: Higher fatigue strength, suitable for structures that endure long-term repeated stress.
- 7178-T6510: Slightly lower fatigue strength, suitable for applications that do not require frequent stress changes.
Tensile Strength (Ultimate)
7178-T6510 has slightly higher tensile strength than 7178-T651, meaning it can endure higher stress under tensile loading. Tensile strength refers to the maximum stress a material can withstand while being stretched and is an important parameter for measuring material strength.
- 7178-T6510: Slightly higher tensile strength, suitable for applications requiring ultimate load capacity.
- 7178-T651: Slightly lower tensile strength, suitable for applications with relatively lower tensile strength requirements.
7178-T651 Aluminum vs. 7178-T6510 Aluminum Applications
- 7178-T651: Due to its better ductility and fatigue strength, 7178-T651 is widely used in the aerospace field, especially for structural components that require high toughness and fatigue resistance. For example, aircraft wings, fuselage parts, and other components requiring high ductility and fatigue strength.
- 7178-T6510: Due to its slightly higher tensile strength, 7178-T6510 is suitable for applications that require higher strength but are less stringent on ductility, such as certain high-load structural components or parts that require high tensile strength.
Differences in Stress Relief and Stretching Treatment between 7178-T651 Aluminum and 7178-T6510 Aluminum
- 7178-T651: In the T651 state, the metal undergoes solution heat treatment, stress relief (stretching treatment), and artificial aging. Stress relief is achieved by stretching the metal to reduce residual stress, with the amount of stretching usually depending on the type of standard forging product being manufactured (such as thin plates, sheets, rods, or forgings). The stretching operation helps the material achieve better stability, while its ductility and fatigue resistance are optimized in the process.
- 7178-T6510: Similar to the T651 state, but in the T6510 state, the metal undergoes stress relief after solution heat treatment, with the stretching amount depending on the type of product being manufactured (such as extrusions or pipes). In the T6510 state, after the stretching operation, the metal is not fully straightened, meaning its microstructure and grain size are different. The T6510 state is very similar to the T6511 state, but T6511 allows straightening after stretching.