Cold processing of industrial aluminum profiles refers to a collection of processes such as plastic deformation, cutting, and finishing of basic profiles under conditions below the recrystallization temperature of aluminum alloys (mainly processing at room temperature). In the mainstream scenario in the industry, cold working is the core post-processing process after hot extrusion, which is used to correct extrusion defects, give products functional structures, and improve dimensional accuracy and surface quality; a few special precision profiles will also use the direct cold extrusion process.
一. Typical overall cold working process
After the hot extrusion profile has completed cooling, stretching and straightening, initial cutting to length, and artificial aging, it officially enters the cold processing link. The standard processing sequence is as follows:
1. Defect Correction: Correct deformation defects such as angular deviation, plane gap, flaring/closing, longitudinal bending, etc. caused by extrusion through cold rolling.
2. Precision blanking: perform high-precision sawing, laser cutting or milling according to the finished product size to obtain standardized processing blanks
3. Plastic forming processing: Complete plastic deformation such as bending, stamping, and drawing according to product requirements to change the overall shape of the profile
4. Cutting and finishing: processing holes, threads, slots and other functional structures through CNC, drilling and tapping and other processes
5. Finishing and deburring: remove processing burrs, sharp edges, and polish surface defects
6. Inspection transfer: After full inspection of dimensions and geometric tolerances, transfer to surface treatment or assembly process
二. Detailed explanation of core cold working process
1. Cold rolling correction
This is the basic cold working process of extruded profiles, specifically correcting the deformation defects produced during hot extrusion and cooling:
For angle deviations, plane gaps, and flaring/closing defects, upper and lower pairs of rollers are used for rolling; for longitudinal bending, upper and lower staggered rollers are used
The processing follows the fixed sequence of "plane gap → angle → expansion → closing → longitudinal bending", and is gradually corrected to avoid stress superposition
Test roll debugging parameters before formal batch processing, and confirm that the shape accuracy and surface quality are qualified before production.
2. Plastic forming cold processing
The shape of the profile is changed through plastic deformation at room temperature without destroying the integrity of the material. At the same time, work hardening occurs to increase the strength:
Cold bending: including three mainstream methods: stretch bending, roll bending and pressure bending
Tension bending: bending while applying axial tension, uniform inner and outer stress, high precision, no wrinkles on the surface, suitable for large radius arc profiles
Rolling bending: continuous feed bending through multiple sets of rollers, simple equipment, suitable for arc processing of long-length profiles
Press Bending: Mold stamping and bending, high efficiency, suitable for batch bending of small size and small radius
Punching and punching: Use punches and molds to complete punching, grooving, notching, profiling, etc., with high efficiency and good consistency. It is the preferred process for mass production of connecting holes and mounting locations.
Cold drawing: Pull the profile through a precision mold to reduce the cross-sectional size, improve surface finish and dimensional accuracy. It is mostly used for precision pipes, rods and small special shapes.
Cold extrusion: The blank is extruded from the mold under high pressure at room temperature to directly form high-precision complex cross-section profiles. It is mostly used for small precision parts and can reduce the amount of subsequent processing.
3. Cutting cold processing
Processing functional structures through material removal is the core process of customized industrial profiles:
CNC Milling: Complete slot milling, surface milling, special-shaped holes, and complex contour processing through CNC machining centers, with an accuracy of up to ±0.05mm, suitable for high-precision industrial components
Drilling and Tapping: Processing of installation holes and connection threads, divided into manual drilling and tapping and CNC automatic drilling and tapping, is the basic process for profile assembly and connection.
Precision Sawing: Use CNC sawing machine to achieve angle sawing and fixed-length cutting, with high end face flatness and no need for secondary trimming
4. Finishing
The finishing process of cold processing ensures the appearance and safety of the finished product:
Deburring: Remove sharp edges and burrs caused by cutting and stamping to avoid scratches and assembly interference
Grinding and polishing: partial polishing to target surface defects, or brushing and polishing on the exterior surface to improve surface texture
三. Core technical characteristics of cold processing
1. High processing accuracy, capable of achieving dimensional tolerances of ±0.01~0.1mm, meeting industrial precision assembly needs
2. After processing, the material undergoes work hardening, the strength and hardness are improved, and the mechanical properties are better.
3. No heating is required for normal temperature processing, the profile has small deformation and no oxidation, and the surface quality is easy to control.
4. The process is highly flexible, and processes can be freely combined according to product needs, adapting to small batch customized production.
