How Does Friction Welding Technology Enhance Engine Valve Durability and Performance?​

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Modern high-performance engine valves are often composite structures, meaning the stem and the head can be made from different materials optimized for their specific function. This is made possible by friction welding, a solid-state joining process that is a cornerstone of advanced valve manufacturing. In this process, the two parts—for example, a hollow sodium-filled stem and a hardened head—are rotated under high pressure. The friction generated at the interface creates heat, plasticizing the materials without melting them.

When the rotation stops, a final forge pressure is applied, creating a metallurgical bond that is often stronger than the base materials themselves. This technology allows manufacturers to create valves that are lighter (reducing inertia for higher RPM limits), more durable, and better at heat dissipation. For instance, a stainless steel head with excellent heat and corrosion resistance can be joined to a martensitic stem with high wear resistance. Our friction welding machines provide precise control over rotation speed, pressure, and burn-off length, ensuring a perfect, defect-free weld every time, which is verified through 100% non-destructive testing.