Gravity Casting
Gravity casting, in simple terms, relies on the natural force of gravity to fill the casting mold with aluminum, making it an early but cost-effective casting method. Despite its simplicity and high production efficiency, this process has drawbacks. During pouring, inclusions and gas may become incorporated, resulting in porosity defects. Gravity casting wheels are susceptible to shrinkage, leading to poor internal quality. Moreover, the limited fluidity of liquid aluminum may reduce the yield for complex wheel hub shapes. Consequently, the automotive wheel manufacturing industry rarely employs this method due to its inherent challenges.
Optimize your wheel production process by exploring advanced casting methods that overcome the limitations associated with gravity casting.
Low-Pressure Casting
Low-pressure casting, a highly efficient process, involves injecting liquid aluminum into a mold under pressure, resulting in wheels with superior density and strength compared to gravity casting. This method, known for its streamlined pouring system and impressive liquid metal yield of up to 90%, is the preferred choice for aluminum wheel production among domestic manufacturers.
While low-pressure casting offers unmatched quality, it has drawbacks, including a longer casting time, time-consuming refilling and mold changes, and higher equipment investment. Despite these challenges, its unparalleled benefits make it a strategic choice for those prioritizing top-notch quality in aluminum wheel manufacturing. Consider the advantages of low-pressure casting for your next wheel production project.
Forging Method
The manufacturing process of forged aluminum wheels involves hot forging, RM forging, cold spinning, heat treatment, machine work, and shot blast, culminating in surface finishing. Forging induces a solid-to-solid transformation, shaping the wheel through beating, pressure, and forging, resulting in higher mechanical properties compared to casting. These wheels boast high strength, excellent corrosion resistance, and precise sizing, with superior strength, toughness, and fatigue strength due to aligned grain flow and force direction. The typical elongation rate of 12%~17% allows forged aluminum wheels to effectively absorb road vibrations and stress.
Despite these advantages, the notable drawback of forged aluminum wheels is the higher production cost associated with numerous processes. While luxury cars often feature forged wheels, most automakers opt for cast wheels due to cost considerations. However, leading domestic wheel manufacturer CITIC Dicastal has successfully entered the passenger car forging wheel production line, compressing forging wheel costs and supplying original wheels for domestic joint ventures. Explore the superior qualities of forged aluminum wheels for enhanced performance and durability.
Squeeze Casting
Squeeze casting, also known as liquid die forging, combines casting and forging in a single process, where metal liquid is directly poured into an open metal mold. Pressure from a punch facilitates smooth filling, shaping, and crystallization of the metal, eliminating casting defects like porosity and shrinkage. This results in a dense structure with superior mechanical properties compared to low-pressure casting, at a significantly lower cost. However, like traditional forging, milling is required for spoke molding. Japan leads in automotive aluminum wheel production using squeeze casting, employing computer-controlled automation for precision throughout the process. Embracing squeeze casting is a global trend in automotive aluminum wheel production due to its efficiency, defect-free results, and cost-effectiveness. Explore the advantages of squeeze casting for top-quality, cost-efficient aluminum wheel manufacturing.
Specialty Molding: Spinning Technology
Spinning technology, initially introduced in Japan, is a unique casting method where the wheel rim is cast as a whole and then undergoes rotary pressure processing. This process alters the internal molecular arrangement, resulting in a higher density of fibrous structure, akin to forged rims. Spinning rims exhibit qualities such as quality, strength, and elongation comparable to forged counterparts but are more cost-effective and easier to produce. Although MAT spinning technology ensures a relatively cost-effective wheel manufacturing process, its limited application domestically is due to less mature technology and higher costs. Explore the advantages of spinning rims for cost-efficient yet high-quality wheel production.
