Analysis of Reasons for Unsatisfactory Mechanical Properties of Aluminum Profiles and Solutions

Main Cause Analysis:

① The aluminum profile extrusion temperature is too low, and the extrusion speed is too slow, causing the profile's outlet temperature on the extruder to not reach the solution heat treatment temperature and failing to achieve solution strengthening;

② There are too few fans at the profile outlet and insufficient airflow, resulting in slow cooling, preventing the profile from dropping below 200℃ in the shortest time, causing coarse Mg2Si to precipitate prematurely, thereby reducing the solution phase and affecting the mechanical properties of the profile after heat treatment;

③ The ingot composition is non-compliant, and the Mg and Si content in the ingot does not meet the standard requirements;

④ The ingot has not undergone homogenization treatment, causing the Mg2Si phase precipitated in the ingot structure to be unable to re-dissolve during the short extrusion time, resulting in insufficient solution and affecting product performance;

⑤ Improper aging process, poor hot air circulation, or incorrect thermocouple installation, leading to insufficient aging or over-aging.

Solutions:

① Properly control extrusion temperature and speed to ensure the profile's outlet temperature on the extruder remains above the minimum solution temperature;

② Strengthen air cooling conditions; if possible, install atomized cooling equipment to meet the minimum cooling gradient requirement for 6063 alloy;

③ Strengthen quality management of ingots;

④ Perform homogenization treatment on ingots;

⑤ Reasonably determine the aging process, correctly install thermocouples, and properly place profiles to ensure smooth hot air circulation. Geometric dimension deviations.