Views: 0 Author: Site Editor Publish Time: 2025-03-03 Origin: Site
1. Determine heat treatment requirements
Treatment type:
Solution heat treatment: Heat the forging to 460-480 ° C (860-900 ° F) for 7075 minutes to dissolve the alloy elements into a solid solution, and then quench.
Artificial aging: For 7075-T6, aging at 120-130 ° C (250-265 ° F) for 24 hours can improve strength (e.g. tensile strength of 550-570 MPa).
T73 tempering: Additional aging steps (e.g. 107 ° C followed by 177 ° C) enhance the stress corrosion resistance commonly seen in the aerospace industry.
Purpose: To specify whether maximum strength (T6), corrosion resistance (T73), or stress release (T651 after tension) is required.
Important reason: Incorrect handling can damage performance, for example, insufficient aging can reduce strength, and excessive aging can soften materials.
2. Alloy compatibility
7075 Characteristics: Due to its zinc, magnesium, and copper content, this alloy has a good heat treatment reaction, but is sensitive to precise temperature control.
Risk: Overheating (above 500 ° C) can cause grain growth or melting of low melting point phases, thereby weakening the forging.
What to do: Confirm with Southwest Aluminum that their process meets the heat treatment requirements of 7075 (such as AMS 2770 standard).
3. Dimensional stability
Deformation risk: Rapid quenching after high-temperature treatment can cause warping of forgings, especially thin-walled rings or complex shaped forgings.
Tolerance: Specify post-processing tolerance (e.g. ± 0.5mm for a 500mm outer diameter ring) and inquire if stretching (e.g. T651) is necessary to minimize deformation.
What to do: Discuss pre-processing and post-processing measurements with suppliers to ensure that the final dimensions meet your specifications.
4. Surface quality
Oxidation: High temperatures can form an oxide layer, affecting the appearance or requiring additional cleaning.
Bubbling: Improper quenching may capture gases, leading to surface defects in 7075.
What to do: Request surface inspection post-treatment (such as dye penetrant testing), or specify surface treatments such as polishing or anodizing when needed.
5. Mechanical performance verification
Test requirement: Heat treatment can alter strength, hardness, and ductility. For 7075-T6, it is expected that:
Tensile strength: 550-570MPa
Yield strength: 480-500MPa
Hardness:~ 150-160 HB
What to do: Request post-processing test reports (such as tensile, hardness) and confirm that they meet your standards (such as AMS 4126, ASTM B247).
