Recently, the aluminum alloy is one of the most important methods to achieve the lightweight of automobiles.The hub,is also known as the rim,is the tire inner frame to support the tires of the drum, the center of the metal parts mounted on the shaft.It can be divided into two types: steel wheel hub and aluminum alloy hub. The former is used for heavy-duty cars and ordinary cars,while the latter is extremely used for middle and high-end luxury cars. In today’s automotive market, most automotive owners are using the lightweight aluminum alloy hub instead of steel alloy material.Because thealuminum alloy exhibits the attractive properties,e.g.lightweight,fast heat dissipation,outstanding damping performance, tyre longevity, safe and reliable and good appearance.
Aluminum alloy is used in the fabrication of aluminum wheels,including A356,6061 and so on.Among them,A356 alloy is mass selection by cast aluminum alloy wheel hubs. A356 aluminum alloy has the characteristics of small proportion and good corrosion resistance. It is mainly composed of aluminum, silicon, magnesium, iron, manganese, zinc, copper, titanium and other metal elements. Aluminum is about 92%, which is a mature aluminum alloy material.
The aluminum alloy wheel hub is suitable for passenger vehicle than steel wheel hub.At present,the manufacturing process can be divided into three types,e.g. the gravity cast technology, low pressure casting, extrusion casting,semi-solid casting, forging, spinning and a combination of several processes.Squeeze casting and semi-solid casting technology can improve the microstructure of the material, improve the mechanical properties, especially for manufacturing large size, lightweight aluminum wheels; the spinning forming technology is a plastic deformation processing technology developed on the basis of hot forging process. The aluminum wheel hub is formed by spinning process after forging, and the mechanical property of the aluminum wheel hub is increased by more than 18% compared with the same specification of casting aluminum wheel hub, and can reduce the quality of about 20%,the main products are large size, lightweight aluminum wheels and racing wheels.