Flow Forming is a manufacturing procedure that brings forged-like qualities to cast aluminum wheels. During the Flow forming process, hydraulic rollers and tremendous pressure combine to ”Form” the inner rim area, forcing the cast material to conform to the profile of a massive steel tooling. Flow forming utilizes a small amount of cast aluminum to stretch along tooling, creating rear barrel from much less material. 🤔 Sooooo, why does that matter? Simply put, utilizing flow forming techniques during the manufacturing process, the end product will be stronger, lighter and more precise than traditional cast wheel forming.
- 1: Wheel face (center spoke design) and outer lip/barrel is cast using low-pressure die-casting. Rear lip/barrel is not casted into mold, instead will be created during heated rotary forging process.
- 2: Wheel rear barrel is heated and pressure is applied with hydraulic rollers to spread cast aluminum material. Applying equal pressure, the wheel barrel is formed using a precision program and rotating drum die.
- 3: Hydraulic roller pressure is continued until final maximum width is desired. Rear lip of barrel is added at very end of program.
Benefits of flow forming include better mechanical properties of the aluminum and utilization of aluminum material(s) more efficiently. When compared with conventional casting, flow formed wheels have greater precision accuracy, better surface finish quality, material hardening, and optimized grain structure. Flow forming not only creates a superior UTV wheel, but also is more efficient in the manufacturing process.
Grain Structure Matters
Cast UTV wheels do not have uniform grain structure, grain flow, or directional strength. During the casting process, slurry is poured into a mold, and as this slurry cools, dendrites form, which eventually turn into grains. These grains are not uniform, as some may be small, large, coarse, and/or fine, which results in grain boundary voids. When there are voids in a manufactured component, this means that that component will have very little impact or fatigue resistance.
Flow Forming produces wheels in which the grains are deliberately aligned in the direction of maximum strength, resulting in exceptional fatigue and impact resistance. Stretching the aluminum's grain structure longitudinally, flow forming greatly increases aluminum's strength and fatigue resistance. Grain flow directly affects the material’s mechanical properties since it determines the direction that the underlying grains push or pull when under stress or fatigue.