In recent years, with the rapid development of the automotive, aerospace and computer industries, higher requirements have been placed on light weight, high toughness and corrosion resistant castings. For aluminum alloy parts, the processing and forming of high-strength, high-toughness, corrosion-resistant alloys, deformed alloys, and the forming process of large and complex alloy parts have become research hotspots for lightweight alloys. However, the mechanical properties of most cast aluminum alloys are currently low tensile strength and low elongation.
With the development of technology, the demand for high-strength, lightweight castings such as die-casting aluminum lamp base, has gradually increased, and the advantages of using aluminum die-casting to prepare aluminum alloy parts have attracted attention. The die casting process (pressure casting) is a special casting process commonly used in the processing industry. The fluid metal or semi-fluid metal is filled into the die casting mold at a high speed under high pressure, and it is formed and solidified under the pressure to finally obtain a casting.
Due to the advantages of high dimensional accuracy, high strength, and high material utilization, die castings are widely used in the manufacture of components with complex shapes and withstand moderate loads. The density of aluminum is only about 1/3 of that of iron, copper, zinc and other alloys. It is one of the die-casting alloy materials that currently meets the requirements for lightweighting. In addition, aluminum has a higher specific strength and specific stiffness, and has good plastic body rheological properties. , Narrow crystallization temperature range, small linear shrinkage and other advantages, easy to form and cut, have higher mechanical properties and corrosion resistance. Based on the above advantages, aluminum alloy has become one of the high-strength and toughness die-casting alloy materials.
Aluminum alloy die castings have excellent weight reduction effects in the automotive, aerospace and other industries. Since the 1980s, the rapid development of the automotive industry has driven the development of related industries, while the development of the automotive industry is mainly focused on intelligent, lightweight, and modular And so on. The technology of aluminum alloy castings, engineering plastics, and carbon fiber replacing cast iron castings has developed rapidly. Among them, more than 40 kinds of components such as heat exchangers, engine cylinders, water pumps, die-casting aluminum motor shell, and wheels in automobiles are casted with aluminum alloy.
With the development of high-strength and toughness die-casting technology, in the 1990s, Europe developed a series of high-strength and toughness die-casting aluminum alloys, and integrated the industry chain, including the research and development of aluminum alloys, industrial design of parts, and supporting equipment for die-casting machines. The characteristics and classification of current die-cast aluminum alloys are briefly described, and the research status and development prospects of traditional and new die-cast aluminum alloys are introduced.
The composition and content of the die-cast aluminum alloy have a significant impact on the mechanical properties of the casting. For the performance requirements of different die-casting aluminum parts, different die-casting processes and corresponding aluminum alloy components should be selected. At present, die-cast aluminum alloys are widely used in the industrial field. They are Al-Si binary alloy systems, Al-Mg binary alloy systems, Al-Si-Mg alloy systems, Al-Si-Cu alloy systems, etc. The aluminum alloy model and composition are shown in Table 1. Generally, the main alloy elements added to the traditional die-cast aluminum alloy are Si, Fe, Cu, etc. The addition of Si element can enhance the fluidity of the aluminum alloy. The addition of Fe element is conducive to the demoulding of the die casting. The addition of Cu element can enhance The strength of castings and the addition of various alloying elements make aluminum alloys have different properties and advantages and disadvantages.