Spray forming is a process of atomizing the liquid flow of alloy into small droplets by high pressure inert gas, flying and cooling in high-speed air flow, and depositing into blank before it has not yet been completely solidified. It has the advantages of fine grain, uniform structure, and can restrain macro segregation, and has the advantages of one step from alloy melting to near final forming, which has attracted great attention.

Aluminum alloy has the advantages of low density, high strength, good toughness and corrosion resistance. It is widely used in aerospace industry as structural materials, and is also actively developing as advanced materials for automobiles and used in high-grade car engines.

Casting technology is the main method of traditional aluminum alloy preparation, but it is difficult to meet the needs of high performance aluminum alloy. Firstly, it is difficult to further improve the strength, plasticity, rigidity, heat resistance and corrosion resistance of traditional technology; Secondly, in the process of pursuing high performance, the casting process cost increases rapidly due to the increase of equipment and the decrease of finished product rate; Third, because of the increase of alloy content, plasticity tends to decrease, so the cost of subsequent pressure processing increases and the yield of finished products decreases. Therefore, the high cost of production greatly improves the threshold of advanced aluminum alloy and seriously affects the development of the overall market scale. In these aspects, spray forming technology has the double advantages of performance and comprehensive cost, which can reduce the threshold of use of advanced aluminum alloy, further improve the performance, realize the replacement of steel with aluminum in a certain range, so as to cultivate the market of advanced aluminum alloy quickly, and to promote the jet forming process to obtain the scale cost advantage. Therefore, spray forming technology will become the main production process of advanced aluminum alloy.

At present, the high performance aluminum alloy materials which have been successfully sprayed are mainly as follows:

(1) High strength aluminum alloy. For example, Al Zn system super high strength aluminum alloy. Because of the wide range of solidification and large difference in specific gravity of Al Zn alloy, the macrosegregation and hot cracking tendency are easy to be produced when traditional casting method is used. The rapid solidification characteristics of spray forming technology can solve this problem well. It has been applied to aerospace vehicle components and key parts such as connecting rod and axle support seat of automobile engine in developed countries.

(2) High ratio and high modulus aluminum alloy. Al Li alloy is a kind of structural material for aerospace and aviation with its low density and high elastic modulus. Ingot metallurgy has limited the full play of the potential of Al Li alloy. The rapid solidification technology of spray forming has opened up a new way for the development of Al Li alloy.

(3) Low expansion and wear-resistant aluminum alloy. For example, hypereutectic Al Si system has high strength wear-resistant aluminum alloy. The alloy has the advantages of low thermal expansion coefficient and good wear resistance, but when traditional casting technology is adopted, the coarse primary Si phase will be formed, which leads to the deterioration of material properties. The rapid solidification characteristics of spray forming effectively overcome this problem. At present, the injection forming Al Si alloy has been made into the inner liner of the cylinder of the car engine in developed countries.

(4) Heat resistant aluminum alloy. For example, Al Fe V SI system is heat resistant aluminum alloy. The alloy has good room temperature, high temperature, strong toughness and good corrosion resistance. It can be used in the temperature range of 150-300 ℃ or higher. Some of the alloys can be used instead of titanium alloy and heat-resistant steel working in this temperature range to reduce weight and reduce cost. The spray forming process can directly produce the blank with the characteristics of rapid solidification structure, compact and large size directly from liquid metal through the minimum process, so that the problems of traditional technology can be solved.

(5) Aluminum based composite. A "sprayco deposition" technology was developed by combining spray forming technology with the preparation technology of aluminum matrix composite, which solved the segregation problem of reinforced particles.