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The objectives for the development of a new high strength aluminium based bearing material are explained. To satisfy these objectives a new material was developed and the composition and structure of this material are described. In the initial phase of development the material successfully passed different internal tests, which are described in the article. However, tests by engine manufacturers indicated a tendency to seizure problems. To study this performance characteristic a test procedure was developed, which allowed a better evaluation of the seizure properties. With use of this test procedure, the composition of the new material and the bearing production process were able to be modified such that resistance to seizure was significantly increased. The composition and the structure of this new material, AlSn10Ni2MnCu, is described and the manufacturing process briefly explained.

Passenger car engines have been equipped with cast crankshafts since 1950. However, their use as opposed to the steel counterparts does increase the wear rate of plain bearings. If the surface finishing operation carried out on nodular cast iron leaves an unsuitable surface texture, the bearing is likely to suffer extensive wear. Previous research examined the effect of different machining methods on the wear behaviour of three-layer high-strength bearings. Unfortunately, it did not prove possible to complete a thorough, systematic investigation of the effects of all the individual factors, even using sophisticated diesel engine tests, since the parameters concerned are too closely interrelated to be isolated. It was aimed at developing a straightforward and financially feasible test procedure to determine the wear mechanism operating in the semi-fluid friction region.

Developments of diesel and gasoline engines in the last years demand for further improved bearing materials. The development of new bearing materials and their testing on test benches are presented. For high performance aluminum three-layer bearings the introduction of a galvanically deposited CuSn-bonding layer instead of Ni as commonly used improved the emergency running properties and the service life. Using the same CuSn-alloy as an intermediate layer between overlay and Ni-strike of conventional CuPb-three-layer bearings the service life of bearings in high powered engines could be improved. The mentioned development variants have been developed to production stage.

Part 1 of the paper dealt with the development of CuSn-layers for heavy duty application engine bearings. Another important development in this field is the use of the physical vapor deposition for the manufacture of new bearing materials. A report is presented on a sputtered overlay on an alloy base AlSn20 for steel-CuPb-three-layer bearings. It is shown from test bench results and present practical experience that the wear resistance and fatigue strength of this type of bearing surpasses that of all known bearing materials used for this function. The process has been developed to production stage and small series are under production in a pilot plant.