Automotive Turbocharger Impeller Machining

The machining of automotive turbocharger impellers (primarily referring to the compressor impeller on the compressor side) is a core aspect of precision manufacturing, aiming to achieve high rotational speeds (up to 250,000 rpm), high precision (micron-level), and resistance to high temperatures and fatigue. The main processing methods are casting and full machining (CNC machining). The former has low cost but limited precision, while the latter is suitable for high-end models and can be directly milled from aluminum alloy bars, improving strength and surface finish. In recent years, five-axis linkage machining centers and UG software programming have become mainstream technologies, ensuring efficient machining of complex blade surfaces.

Main Types of Impeller Machining

• Cast Impellers: Formed by aluminum alloy casting, followed by simple machining. Suitable for low- to mid-range turbochargers, low cost, but prone to porosity defects.
• Fully Machined Impellers: Starting from forged aluminum alloy bars, directly milled using five-axis CNC machine tools, high precision, strong durability, commonly used in high-performance engines. The material is mostly high-strength aluminum alloy (such as 6061 or 7075) to withstand high-speed rotation.

• Finishing Blade Milling: Transferred to a five-axis linkage machining center for blade surface milling. Five-axis allows the tool to approach complex blades from multiple angles, avoiding interference and achieving high-precision forming of radial or backward-curved blades. The blade surface is designed with ruled surfaces to facilitate side milling and improve efficiency.