A method for manufacturing high-strength and tough aluminum alloy wheel hubs for large automobiles by semi-solid rheological deformation

Abstract

A method for manufacturing a high-strength and tough aluminum alloy wheel hub for semi-solid forming large automobiles, which mainly includes preparation of high-alloyed materials, semi-solid rheological forming and casting heat treatment. The preparation of high-alloyed materials is to melt the A356.2 alloy ingot and the Al-Cu master alloy ingot with a copper content of 20% at a ratio of 10:1, and then pour it into a transfer bag to add Al-Zr-B-O and Al- The Sr-RE master alloy is modified and refined, and the melt is degassed and slag-purified with a special injection device; then electromagnetic stirring is designed at the bottom of the static furnace and the upper end of the riser to perform composite electromagnetic stirring. Semi-solid rheological molding is to shape the above materials in the semi-solid temperature range of 615-625°C by pressurized filling. The heat treatment of castings adopts continuous variable temperature homogenization treatment, solid solution treatment and step aging treatment. The elongation, tensile strength, and yield strength of the aluminum wheel manufactured by the above methods meet the requirements for supporting large vehicles.

Description

technical field [0001] The invention relates to the technical field of manufacturing aluminum alloy wheels for automobiles, in particular to a method for manufacturing high-strength and tough aluminum alloy wheels for large automobiles through rheological deformation in semi-solid state. Background technique [0002] Aluminum alloy wheels have the advantages of light weight, good comfort, and beautiful appearance. At present, the utilization rate of aluminum alloy wheels in cars and sports cars has exceeded 90%. However, the mechanical properties of aluminum wheels made of Al-Si-Mg as the main material cannot reach large Vehicles (mainly referring to large passenger cars, trucks, RVs, off-road vehicles, etc.) require high-performance wheels. Therefore, except for some high-end large wheels that use expensive forged or spun aluminum wheels, many large wheels still use Steel wheels with high precision, low dimensional accuracy, and a single shape. [0003] Compared with ordin...

AI Technical Summary

Problems solved by technology

In recent years, with the continuous progress of new materials and wheel manufacturing technology, breakthroughs have been made in the manufacturing technology of large-diameter and high-strength aluminum wheels in the world. Developed countries such as the United States, Germany, and Japan have successfully developed aluminum wheels with a strength exceeding Aluminum wheels with 50% of ordinary aluminum wheels have begun to be configured on high-end large vehicles; but forging and spinning not only require large investment and low product qualification rate, but also can only produce wheel shapes with simple shapes, and the size of the wheel hub is limited (cannot production of wheels above 22 inches); the American company has successfully developed a 20-28-inch aluminum wheel with a new alloy material system and semi-solid molding method, and its tensile strength has reached 350MPa, and its yield strength has reached 260MPa, exceeding Al-Si-Mg More than 50% of the system meets the requirements for supporting large-scale automobile wheels. At present, it has an obvious cost-effective advantage in the international market, but the technology is kept secret

Although domestic institutions have developed Al-Zn-Mg-Cu high-alloyed materials, problems such as poor casting fluidity and alloy composition segregation have not been resolved; some other companies are trial-producing aluminum-based composite material wheels, but the strength and toughness of the materials cannot be solved. Therefore, the domestic industry is eager to make a breakthrough in the material preparation and development technology of large wheel aluminum hubs.

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