Aluminum Profile Extrusion Die Manufacturing Technology

The manufacturing of aluminum extrusion dies is also one of the key factors determining their quality and service life. Because aluminum extrusion dies have a series of characteristics, they impose certain special requirements on the die-making technology for aluminum profiles:

(1) Due to the extremely harsh working conditions of aluminum alloy extrusion dies, which need to withstand high temperatures, high pressures, and high friction during the extrusion process, it is necessary to use high-strength, heat-resistant alloy steel. The processes of smelting, casting, forging, heat treatment, electrical machining, mechanical processing, and surface treatment of these steels are all very complex, which brings a series of difficulties to die manufacturing.

(2) To improve the service life of the dies and ensure the surface quality of the products, the roughness of the mold cavity working surface is required to reach 0.8-0.4 μm, and the roughness of the die plane should be below 1.6 μm. Therefore, special polishing processes and polishing equipment are needed during die making.

(3) As extrusion products tend to develop in the directions of higher, more precise, and sharper profiles, some profiles and tubes require wall thicknesses reduced to around 0.5 mm, with extrusion tolerances reaching ±0.05 mm. To extrude such ultra-high-precision products, the manufacturing accuracy of the dies needs to reach 0.01 mm. Traditional processes are fundamentally unable to produce these dies, thus requiring updated techniques and the use of new specialized equipment.

(4) The cross-sections of aluminum profiles are very complex, especially ultra-high-precision thin-walled hollow aluminum profiles and multi-porous hollow wall aluminum profiles. They require the use of special extrusion die structures, often with multiple shaped cavities on a single die, with thickness variations in different sections changing sharply, complex related dimensions, and many rounded corners, which brings a lot of challenges to die processing and heat treatment.

(5) Aluminum profile extrusion products come in a wide variety with small batch sizes and frequent die changes, requiring dies to be highly adaptable. Therefore, it is necessary to improve die manufacturing efficiency, shorten the die-making cycle as much as possible, quickly change die-making programs, accurately process dies according to drawings, and minimize die repair work.

(6) As aluminum alloy extrusion products are applied more widely and have a very broad range of specifications, there are small dies weighing just a few kilograms with dimensions of 100mm×25mm, as well as large dies weighing over 2000kg with dimensions of 1800mm×450mm. There are small extrusion shafts weighing just a few kilograms with dimensions of 65mm×800mm, as well as large extrusion barrels weighing over 100t with dimensions of 2500mm×2600mm. The huge differences in die and tooling specifications and quality require completely different manufacturing methods and procedures, as well as entirely different processing equipment.

(7) There are many types of extrusion dies, with complex structures and high assembly precision requirements. In addition to requiring special processing methods and specialized equipment, it is also necessary to use special tooling, fixtures, cutting tools, and specific heat treatment methods.

(8) To improve the quality and service life of dies, besides selecting appropriate materials and optimizing the design, it is also essential to adopt the best heat treatment processes and surface strengthening techniques to achieve moderate die hardness and high surface quality. This is particularly important for extrusion products with especially complex shapes and dies with special structures.

The processing technology of stamping molds is slightly different from general mechanical manufacturing processes; it is a highly complex and specialized technology with a wide range of applications. In order to produce high-quality and long-lasting molds, it is necessary not only to select and prepare high-quality mold materials, but also to establish reasonable cold working processes, electrical machining processes, heat treatment processes, and surface treatment processes.