The automotive industry continues to develop based on the needs of energy, safety, comfort and other factors. The automotive industry's development needs for materials are in the era of application of aluminum-magnesium alloys to replace steel, cast iron and other energy-consuming high-quality materials. Traditional body parts are mainly made of steel sheet stamping or hydraulic bulging or sheet welding. If aluminum alloy is used, high strength and high toughness are required. The application of aluminum alloy has the advantage of highly integrated parts. The performance requirements for different parts are different. Some need to improve their elongation and some need to improve the corrosion resistance. With the development of high vacuum die casting technology, processing of die-casting aluminum parts requires more excellent aluminum alloys with various properties.
In order to realize the demand for high-plasticity aluminum alloys, scholars from Germany and Japan have conducted research on high-plasticity Al-Si-Mg alloys based on high-vacuum technology since the 1990s. New die-casting aluminum alloys developed by Rheinland Aluminium Company: Magsimal-59, Sila⁃font-36 and Castasil-37, control the Fe content in the alloy to <0.2% to ensure the toughness and strength of the die-casting aluminum motor casing, A mold sticking phenomenon occurs, and at the same time, 0.5% to 0.8% of Mn element is added to the alloy. After testing, the elongation of the Magsimal-59 alloy standard round bar sample in the as-cast state can reach 17%, and it has been used in manufacturing automobile doors.
At present, many domestic enterprises and research institutes are developing high-strength aluminum alloys suitable for automotive body structural parts. For example, Ningbo Heli Mould Technology Co., Ltd. and Shanghai Jiaotong University School of Materials Science and Engineering have jointly developed high-elongation heat-resistant cast aluminum alloys. During the cooperation period, a high-elongation heat-resistant cast aluminum alloy and a method for preparing it by pressure casting were developed. The alloy belongs to the Al-Si-Mg series alloy, which explains the content of Si, Cu, and Mg, and trace elements Sc, M ( At least one element of Ti, Zr, V) is specified. The yield strength of the die-casting state can reach 169 MPa, the elongation can reach 10.0%, the high-temperature tensile strength at 200 ° C can reach 190 MPa, the high-temperature elongation can reach 14.0%, Excellent thermal performance, and can be applied to automotive parts such as die casting aluminum pump casing, without solid solution heat treatment, meeting the needs of lightweight development of automobiles.
Aluminum Heat Sink
In summary, the current research on new high-strength and toughness die-cast aluminum alloys mainly focuses on Al-Si-Mg series. Due to the addition of Mg element to Al-Si series alloys, Mg2Si can be formed, and solid solution can be formed during solid solution treatment and strengthen Alloy, and Mg element can also form a spinel film with high corrosion resistance on the surface layer of the alloy liquid, improving the corrosion resistance of the casting. In theory, the comprehensive strengthening effect of Cu element on Al-Si alloy is more significant. Compared with Mg element, Cu element is more likely to form nucleus in aluminum alloy, and its performance is improved after heat treatment, but the dissolution rate of Cu element in aluminum alloy is relatively Low, its application in Al-Si based alloys is limited. The research on the new high-strength and toughness properties of Al-Si-Cu series alloys needs further exploration, which is of great significance for the research and development of new high-strength and tough aluminum alloys.