The wheel hub is a barrel-shaped metal part that supports the tire inside the tire and is mounted on the shaft. The wheels are mainly divided into iron wheels and light alloy wheels according to materials, and light alloy wheels are mainly aluminum alloy and magnesium alloy products. In today's automotive market, iron wheels are rare, and most models use aluminum alloy wheels.
Aluminum Alloy Wheels are more suitable for passenger cars than steel wheels. At present, their manufacturing processes can be basically divided into three types. The first is casting. At present, most automobile manufacturers choose to use casting processes. The second is forging, which is mostly used in high-end sports cars, high-performance cars and high-end modified markets. The third one is more special. It is the MAT spinning technology first used by Japan's Enkei Company. At present, this technology is not as widely used in China as the first two.
Aluminum Alloy Wheels
1.Gravity casting method
In simple terms, gravity casting is mainly based on the gravity of aluminum water to fill the mold, which is an early casting method. This method has low cost, simple process and high production efficiency. However, during the pouring process, the inclusions are easily entangled in the casting, and sometimes they are entangled with gas, forming pore defects. Wheels produced by gravity casting are prone to shrinkage and shrinkage, and the internal quality is poor. In addition, the limitation of the fluidity of the aluminum liquid may also lead to a low yield of the wheel with complicated shapes. Therefore, the automotive wheel manufacturing industry has rarely used this process.
2.Low pressure casting method
Low pressure casting is a process in which aluminum liquid is filled into a mold under pressure and solidified and crystallized under pressure. In the same situation, compared with gravity casting, the internal structure of the low-pressure Casting Aluminum Wheels is denser and stronger. In addition, low pressure casting uses pressure filling and replenishment, which greatly simplifies the pouring system structure, so that the metal liquid recovery rate can reach 90%. At present, low-pressure casting has become the preferred process for aluminum wheel production, and most domestic aluminum alloy wheel manufacturing companies use this process for production.
Hot forging-RM forging-cold spinning-heat treatment-machining-shot peening-surface treatment.
Forging is the change from solid to solid, and the wheel style is formed by means of beat, press, forging, etc. This process does not change the liquid phase, all are solid changes. Therefore, its mechanical properties are higher than those of casting, and it has the advantages of high strength, good corrosion resistance, and accurate dimensions. The flow direction of the grains is consistent with the direction of the force, so the strength, toughness and fatigue strength are significantly better than the cast aluminum wheels.
4. Squeeze casting method
Squeeze casting, also known as liquid die forging, is a process that combines the characteristics of casting and forging-pouring a certain amount of metal liquid directly into an open metal mold, and applying a certain pressure on the liquid metal through a punch, make it fill, shape and crystal solidify, and produce a certain amount of plastic deformation during the crystallization process.
5. Special molding: spinning technology
Spinning technology was first put into use in Japan. Strictly speaking, it should be regarded as a type of casting. It refers to the use of special equipment to rotate and pressurize the force after the wheel is cast. The internal molecular arrangement of the metal has changed, and the specific split surface has a higher density of fibrous than the general cast product, thereby changing the overall metal mechanics process.
The above are the five molding processes of aluminum alloy wheels introduced by Low Pressure Aluminum Alloy Wheels Manufacturer.