Not sure about the T4, T5, and T6 materials of aluminum profiles? This article helps you answer

As a by-product of the extrusion process, small, almost invisible lines sometimes appear on the surface of the profile. This is a result of the helper tools when extruding, and other surface treatments can be specified to remove these lines. In order to improve the surface finish of the profile section, some minor surface treatment operations can be performed, such as end milling after the main extrusion process. These machining operations can be specified to improve the geometry of the surface by reducing the overall surface roughness of the extrusion profile to improve the part profile. These treatments are typically specified in applications that require precise positioning of parts or where mating surfaces must be tightly controlled.

We often see that the material column is marked with 6063-T5/T6, or 6061-T4, etc. The 6063 or 6061 in this mark is the grade of the aluminum profile, and T4/T5/T6 is the status of the aluminum profile. So what's the difference between them?

For example: To put it simply, the 6061 aluminum profile has better strength and cutting performance, high toughness, good weldability and corrosion resistance; the 6063 aluminum profile has better plasticity. It can make the material achieve higher precision; at the same time, it has higher tensile strength and yield strength, shows better fracture toughness, and has high strength, wear resistance, corrosion resistance and high temperature resistance.

The T4 state is: solution treatment + natural aging, that is, the aluminum profile is cooled after being extruded from the extruder, but is not put into an aging furnace for aging. The hardness of the unaged aluminum profile is relatively low and the deformability is relatively good, which is suitable for the later stage. Bending and other deformation processing.

The T5 state is: solution treatment + incomplete artificial aging, that is, after extrusion, it is air-cooled and quenched, and then transferred to an aging furnace and kept at about 200 degrees for 2-3 hours. The state of the aluminum after it is released. Aluminum in this state has relatively high hardness and a certain degree of deformability, and is the most commonly used in curtain walls.

The T6 state is: solid solution treatment + complete artificial aging, that is, it is water-cooled and quenched after extrusion. The artificial aging after quenching is higher than the T5 temperature and the holding time is longer, thereby achieving a higher hardness state, which is suitable for Occasions where material hardness requirements are relatively high.

The mechanical properties of different materials and states of aluminum profiles are detailed in the table below:

Mechanical properties of profiles

Yield strength: It is the yield limit of a metal material when it yields, that is, the stress that resists trace plastic deformation. For metal materials without obvious yield, the stress value that produces 0.2% residual deformation is specified as the yield limit, which is called the conditional yield limit or yield strength. External forces greater than this limit will cause the parts to permanently fail and cannot be restored.

Tensile strength: When the aluminum yields to a certain extent, its ability to resist deformation increases again due to the rearrangement of the internal grains. Although the deformation develops rapidly at this time, it can only increase with the increase of stress until the stress reaches the maximum value. After that, the ability of the steel to resist deformation was significantly reduced, and large plastic deformation occurred at the weakest point, where the cross-section of the specimen rapidly shrank, causing necking until fracture and failure.

Webster hardness: The basic principle of Webster hardness is to use a quenching indenter of a certain shape to press into the surface of the pattern under the force of a standard spring. An indentation depth of 0.01MM is defined as a Webster hardness unit. The hardness of the material and the pressure It is inversely proportional to the penetration depth. The shallower the penetration, the higher the hardness, and vice versa.

Plastic deformation: Plastic deformation is a deformation that cannot recover by itself. Engineering materials and components will undergo permanent deformation after being loaded beyond the elastic deformation range, that is, irrecoverable deformation will occur after the load is removed, or residual deformation, which is plastic deformation.