Characteristics, causes, and solutions of coarse grains in extruded aluminum alloy products

The characteristics of coarse grains in extruded aluminum alloy products are: decreased mechanical properties, easy cracking during cold deformation, and rough surface (resembling orange peel).

The main reasons for the appearance of coarse grains in extruded aluminum profiles are: high heating temperature, long insulation time, slow heating speed, small deformation of cold deformed metal, or annealing at the critical deformation degree.

The solution to the occurrence of coarse grains in extruded aluminum materials is to choose a reasonable heating temperature and holding time for heat treatment; Increase heating speed; For metals that require cold deformation, the degree of cold deformation should be increased and annealing at the critical deformation degree should be avoided as much as possible.