Brief Description of the Sliding Material
KS R20 is a robust bearing material used in gasoline and diesel engines, known for its excellent anti-seizing properties, good embedding capability, and adaptability. It is resistant to oil corrosion and suitable for engines with low to medium loads, with a specific load carrying capacity of up to 50 MPa. KS R20 complies with the EU Directive 2000/53/EC on End-of-Life Vehicles.

Bearing Structure
The bearings consist of a steel back, an intermediate layer of pure aluminum, and an aluminum/tin/copper running layer. The steel back is typically grade DC04 with a hardness of 150-220 HB. The intermediate layer is 0.01 to 0.05 mm thick, while the running layer is 0.2 to 0.5 mm thick with a hardness of 30-50 HB.

Material Characteristics
Key characteristics include a tensile strength of over 150 MPa, a yield point of over 90 MPa, a Young's modulus of 63 GPa, a coefficient of thermal expansion of 24 x 10^-6 k^-1, and thermal conductivity of 50 W/(m·k).

Manufacture of the Sliding Material
The aluminum alloy is produced through vertical continuous casting, followed by mechanical processing and heat treatment. A pure aluminum foil is plated onto the strand, and roll cladding applies the pre-composite onto the steel. Thermo-mechanical treatments finalize the material characteristics.

Plain Bearing Manufacture
KS R20 strips are used to manufacture sliding elements through punching and forming, with final machining to achieve the desired wall thickness and surface design.

Application
KS R20 sliding elements are ideal for main bearings in low to medium-load engines due to their excellent anti-seizure properties and adaptability.

Test Conditions
Tests were conducted with a bearing shell diameter of 47.8 mm, wall thickness of approximately 1.4 mm, sliding velocity of 0.25 m/sec, specific static load of 6.2 MPa, and a test duration of 3 hours.

Chemical Composition of the Running Layer
The running layer consists of 16.5 to 22.5% Sn, 0.7 to 1.3% Cu, with maximum limits for Si, Ti, Ni, Fe, Mn, and other elements, with the remainder being aluminum.

Comparison of Specific Load Carrying Capacity and Wear Behavior
KS R20 shows competitive specific load carrying capacity and wear behavior compared to other materials like KS R21, KS R25, KS R30, and KS R45.