Manufacturing process
T6 aluminum alloy bar after solution heat treatment and water-cooled quenching process, rapid cooling to obtain high strength, but the internal residual stress is larger, easy to deform when directly machining.T651 in T6 based on the addition of cold stretching process, through mechanical stretching to eliminate internal stress, so that the material stress distribution is more uniform, subsequent processing of the T651 aluminum bar stability significantly improved.
Mechanical properties
T6 state aluminum alloy bar has higher tensile strength and hardness (e.g., tensile strength up to 205 MPa), which is suitable for load-bearing structures or mechanical support parts that require high strength. t651 balances strength and toughness through the tensile treatment, and although the ultimate strength is slightly lower than that of t6, the deformation-resistant ability is stronger, which is especially suitable for parts that require precision machining or complex molding.
Processing and Applications
Due to high internal stress, T6 bar needs to be reserved for deformation allowance when cutting or welding, and is commonly used in scenarios that require high strength but average precision, such as architectural brackets and frames, etc. Due to uniform stress, T651 bar can be directly used in areas that require high dimensional stability, such as parts of precision instruments and mold accessories, without secondary leveling after processing, and with a smoother and more uniform oxidation-treated surface.
Surface and Durability
Both of them have good corrosion resistance and oxidized coloring performance. T6 has slightly better corrosion resistance in humid or salt spray environment due to denser grain structure; while T651 has less deformation after welding or deep processing due to elimination of internal stresses, which is suitable for scenarios that require multiple welding or fine surface treatment.
Suggestions for selection
If high strength and high hardness are the priority needs (such as mechanical load bearing shafts and high load connectors), T6 is more suitable; if both processing accuracy, low deformation rate and surface treatment stability are needed (such as precision mold mandrels and complex structural components), T651's comprehensive performance is better.
