[China Aluminum Industry Network] aluminum cracks the main factors: 1. Extrusion temperature of aluminum extrusion is too high, the tensile strength of the metal surface decreases, and cracks occur under the action of friction. 2. Due to friction, the metal surface is subjected to additional tensile stress. When the additional tensile stress is greater than the surface metal tensile strength, cracks will occur. 3. When the extrusion speed of the aluminum profile is too fast, the additional tensile stress on the surface of the metal increases to crack the profile. Solution: Strictly control aluminum extrusion process parameters to ensure reasonable outlet speed and outlet temperature.