What are the reasons for insufficient tensile strength of industrial aluminum profiles.

Most industrial aluminum profiles are 6063-T5 grade aluminum profiles, with a tensile strength of over 160MPa and yield strength of over 110MPa. If the strength cannot be reached, it will affect the performance of aluminum profiles. So what are the reasons for the unqualified tensile strength of industrial aluminum profiles?

1. Unqualified alloy composition

The composition of 6063-grade aluminum profiles is aluminum, magnesium, and silicon. The Mg2Si content in 6063 aluminum alloy profiles should be controlled within the range of 0.75% to 0.80% to minimize the presence of excess magnesium or silicon. At the same time, impurity elements will also affect the strength of industrial aluminum profiles, such as iron. If the content exceeds the standard, the mechanical properties and corrosion resistance of aluminum profiles will be seriously affected. Therefore, strict control should be exercised over the iron element during casting, and a content less than 0.25% is ideal.

2. Defects such as looseness and slag inclusion in aluminum casting rods

Defects in raw materials can also lead to the insufficient tensile strength of industrial aluminum profiles, and the coarse and loose grain size of the cast rod can cause the extruded aluminum profile to have coarse grain size and become brittle.

3. Squeeze ratio is too small

The extrusion ratio is the ratio of the cross-sectional area of the extrusion cylinder to the cross-sectional area of the profile, and the extrusion ratio should be controlled between 20 and 50. A too-small extrusion ratio can lead to insufficient metal deformation, thereby affecting the strength of industrial aluminum profiles. An excessive extrusion ratio is not acceptable as it can cause damage to the mold.

4. Insufficient quenching strength

6063-T5 profiles are generally quenched by air cooling. From the beginning of discharge, strong wind is used to quickly cool the aluminum profile until the temperature drops below 60 degrees Celsius before straightening and sawing. If the temperature drops slowly, it will lead to insufficient quenching and affect the strength of industrial aluminum profiles.

5. Insufficient aging temperature or inadequate control of insulation time

The extruded and quenched aluminum profiles need to be artificially aged in an aging furnace, which should always maintain a high temperature of over 200 degrees Celsius. Insufficient or prolonged insulation of industrial aluminum profiles in the aging furnace can result in the inability to achieve the required tensile strength.

So to produce high-quality industrial aluminum profiles, each link must be strictly controlled, and any chain drop in one link will lead to unqualified industrial aluminum profiles and scrapping.