Research on Design and Manufacturing of Extrusion Profile Mould for Aluminum Structure in Green Building

[China Aluminum Industry Network] Executive summary: There are many varieties of aluminum structural profiles in green buildings, with a wide range of specifications and complex shapes. The technical content of mold design and manufacturing is high, and production technology is difficult. This article only selects a typical difficult profile as an example, analyzes and discusses the design scheme, manufacturing process and innovation points of the mold, and compares the extrusion effect and service life of the mold. It can be seen that high-quality molds play an important role in the industrial mass production of aluminum alloy structural extruded profiles. Keywords: green building, aluminum alloy structure, extrusion material, large-scale double-hole thick-walled pipe (hollow profile) mold design and manufacturing special new structure wide spread shunt die service life 1. green building aluminum alloy extrusion profile die characteristics and technical difficulty analysis 1.1 Overview of green building aluminum alloy extrusion structure of up to more than 100 kinds of species, and a wide range of specifications, most modern aluminum extrusion materials for green construction do not require mechanical processing, and directly as components to use with related parts, Therefore, both the dimensional accuracy and shape accuracy are very high. Structural materials include pipes (including round pipe, square pipe and profiled pipe, all of which are thick-walled pipes; various profiled profiles (including hollow profile, solid profile and semi-hollow profile, and large wall thickness difference) are difficult to form; and All kinds of special bar materials, most of the awards for structural materials are medium-strength aluminum alloys such as 6061, 6005A, 6082, and high-strength and high-toughness aluminum alloys such as 2xxx, 5xxx, and 7xxx. High mechanical properties, b300MPa, excellent weldability, wear resistance, corrosion resistance, cold formability, etc. It also requires industrial mass production.Therefore, different forms of special structural molds are required, such as special diversion Mould and special wide spread shunting die can ensure the forming and dimensional accuracy of different products, and require high service life (requiring 2-3 times longer service life) to ensure mass production.The following is only selected from more than one hundred kinds of extruded materials. A double-hole thick-walled pipe WYY0770 mold with large circumcircle dimension, horizontal ribs, and difficulty in forming is taken as an example to discuss the design and manufacturing technology of aluminum alloy building structural extrusion material molds. Features, WYY0770 pipe section shown in Figure 1 with two holes. Figure 1. Green building structure extruded material - WYY0770 Product Map 1.2 Characteristics and Technical Difficulties of Aluminum Alloy Structural Extruded Materials (1) Green Building Structure Aluminum alloy extruded materials have many varieties, complex shapes, and large dimensional changes. Therefore, it is required to design and manufacture high-quality molds of different specifications, different structures, and different forms. In order to realize industrial production of aluminum alloy structural extrusion materials in large quantities, a large amount of experimental development work is required. (2) The green building aluminum structure extrusion material requires industrial mass production, the first key is to improve the service life of the mold. The development subject requires the life of the extrusion mold to increase 2-3 times on the original basis, the difficulty is very big. (3) The transverse stiffeners of the double-hole thick-walled tubes with transverse stiffeners are difficult to charge. A special structure of the wide spread diversion die and the diverter die is required to expand the metal flow over the die holes and distribute them in two stages. The metal flow rate and the optimization of the extrusion process can ensure the formation of double-walled thick-walled tubes. Technical difficulties are very great. In particular, the formation of large-size thick-walled double-hole tubes and the requirement for ensuring the quality of welding are even more difficult. (4) The green building structure The aluminum alloy extruded material's size and shape precision are required to reach high-precision or ultra-high-precision level, a special structure of the mold is needed to ensure the formation of the profile, and to achieve high precision, but also to ensure The mold has sufficient strength, no deformation, no cracking, no collapse, and sufficient service life. The difficulty is very great. (5) Green building structure Aluminum alloy extruded materials require smooth surfaces, high precision in dimension and shape, and long service life. Therefore, it is necessary to use high-quality mold steel and strict mold heat treatment process and surface treatment process. All machining operations are implemented. CNC process specification can obtain high-quality mold with high strength, high toughness, high precision and low surface roughness. Design basis and technical requirements for WYY0770 large-scale double-hole thick-walled pipe moulds (1) WYY0770 The large double-hole thick-walled pipe alloy has the alloy state of 6005FT6. The extrusion material is delivered by precision water, fog, gas quenching and artificial aging, and the size and shape of the profile are required. The bit precision reaches ultra-high precision level, b300MPa, and has good mechanical properties, wear resistance, corrosion resistance, weldability, cold bending formability and other comprehensive properties. (2) WYY0770 extruded material is a large-sized double-walled thick-walled tube (see Figure 1). The characteristic of double-walled thick-walled tube is that serious wall thickness difference and plane clearance are prone to occur. The double-hole tube is not sufficiently thick due to insufficient charge. WYY0700 double The hole tube is a 450mm wide and 200mm high square tube with a horizontal stiffener. To make a single-hole square tube into a double-hole tube, the difficulty lies in the insufficient charging of this horizontal reinforcing rib, and it requires a high welding quality. The use of an ordinary splitter die can not reach the technical requirements of the extruded double-hole tube. A special combination mold must be designed to ensure the formation and accuracy requirements. (3) WYY0770 large-size double-hole pipe is produced in a 7000-ton extruder. The diameter of the barrel is 418mm. The circumcircle (498mm) of the profile is larger than the diameter of the barrel (418mm). This requires designing a special multi-stage. Expanding the extrusion die and expanding the circumcircle of the split die welding chamber can ensure the profile forming and dimensional accuracy and plane gap size requirements. If 460mm extrusion cylinders are used, metal flow and balance will improve. (4) The four external angles of the WYY0770 double-hole tube are the same as those for the eight internal angles. The geometrical position tolerance value is higher than the GB5237 high-precision level specification, and it is necessary to repeatedly calculate and balance the metal flow distribution to ensure the angular accuracy. The user's requirement to ensure that the accuracy of the two angles of the profile is to ensure the smooth loading and unloading of the profile and the overall flatness. The design and manufacturing of the mold is indeed extremely difficult. (5) It is required to select excellent mold materials, advanced heat treatment and surface treatment processes to ensure that the service life of the mold is increased by 2-3 times. 3. Design and manufacture of green building aluminum alloy structural profiles WYY0770 mold technology solutions and measures to improve service life and innovation point analysis WYY0770 profiles using 418mm (scheme I) extrusion cylinder and 460mm extrusion cylinder on the 7000t extrusion machine (scheme II) Extrusion production, its mold design, production technology analysis is as follows. 3.1 WYY0770 large-scale double-hole tube mold design basis and design parameters shown in Table 1 and Table 2. Table 1 mold design of WY0700 large-sized double-hole tube according to the parameter table Program alloy status Double hole cross-sectional area Cm2 Circumcircle Diameter mm Implementation standards and Accuracy level Extruder tonnage t Squeezing tube straight mm Specific pressure MPa Extrusion ratio l Deformation rate% I 6005FT6 145.225 F492.5 GB5237 High-grade 7000 F418 510 9.45 89.4 II 6005FT6 145.225 F492.5 GB5237 High-grade 7000 F460 421 11.44 91.3