MATERIALS
ADVANCED ALLOYS
How new innovations in alloy development are advancing slide bearing technologies for combustion engines
Wieland L66 and Wieland L67 are derived from CuNi6Sn6 I
n today’s high-performance combustion engines for trucks and passenger vehicles, efficiency and durability are paramount. With
over 200 years of industry expertise, Wieland has developed two advanced CuNi6Sn6 alloys – Wieland L66 and Wieland L67 – to push the boundaries of sliding bearing performance. Although these alloys share the same chemical composition, they are processed differently to meet distinct production volumes and application requirements. This article examines the material science behind these alloys, their optimised manufacturing processes, and the resulting advantages in friction, mechanical properties, and design flexibility.
MICROSTRUCTURAL EXCELLENCE Wieland L66 and Wieland L67 are derived from CuNi6Sn6, a monometallic alloy renowned for its excellent wear resistance and consistent performance. The exceptional tribological properties are
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achieved through a specialised heat treatment that triggers controlled microstructural transformations. One important phenomenon is spinodal decomposition, which refines the alloy’s microstructure at a very fine scale. This process enhances hardness and abrasive resistance while preserving ductility—a critical balance for sliding bearing applications. For the rolled product, Wieland
L66, delivered as a sheet, the bending process used to form sliding bearing bushes capitalises on the alloy’s inherent strength and can even achieve slightly enhanced mechanical properties. Wieland L66 exhibits impressive benchmarks: a hardness of 255HB, a tensile strength of 810MPa, a yield strength of 735MPa, and an elongation of at least 7%. These values underscore its capability to withstand extreme combustion pressures while maintaining peak performance. In contrast, Wieland L67 is
produced as an extruded tube that is subsequently cut to length and processed further. Although Wieland
L67 shows slightly lower mechanical values—with a hardness of 205HB, a tensile strength of 680MPa, a yield strength of 615MPa, and an elongation exceeding 9% - its tribological characteristics remain exceptional and comparable. The phenomenon of spinodal decomposition ensures that both Wieland L66 and Wieland L67 maintain their structural integrity throughout the product lifecycle. As the surface layer wears, a new layer with the same high-performance properties is immediately available, guaranteeing consistent long-term performance.
PROCESS OPTIMISATION The distinct manufacturing routes for Wieland L66 and Wieland L67 reflect the company’s commitment to innovation and cost-effective production – by leveraging state- of-the-art production facilities and equipment, Wieland ensures that every component produced meets the highest standards of quality, durability, and reliability.
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