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There are several all-aluminum cylinder blocks. A typical example is a mono-block cylinder of alusil alloy produced by low pressure die casting. This material's resistance to abrasion and seizure, however, is not satisfactory for motorcycle; in addition, long processing time is another disadvantage. To cope with these problems, the authors developed a light and highly productive all-aluminum cylinder block with a cast-in liner through die casting. The liner is made from powder metallurgy composite (PMC) with 3 to 5 % alumina and 0.5 to 3 % of graphite additives. The PMC reconciles abrasion resistance and machinability. The hardness deterioration of the composite due to the heat at die casting is avoided by using heat-resistant rapidly-solidified powders, made from an aluminum-silecon-iron alloy, for the matrix.

A new double-layer valve seat insert has been developed for use in high performance diesel engine of passenger car. The seat layer is composed of a sintered alloy of a high wear resistance and a high heat resistance. The base layer is composed of a sintered alloy of a higher heat resistance than that of the seat layer. This double-layer valve seat insert was proven to have good wear resistance and heat resistance in a durability test on the diesel engine with a turbocharger system.

A liquid phase sintered valve seat insert has been developed for use in high performance engine. The material consists of Fe-Cr-C sintered alloy in which hard alloys and lubricating alloys dispersed uniformly. High wear resistance can be attained through proper dispersion of these alloys in the matrix. Containing more than 10 % Cr, the matrix material has high heat resistance and creep strength. IN JAPAN MANY CAR manufacturers are now developing new types of maitenance-free engines. These new engines will have a higher performance than that of the present engines. To make high performance engines it is necessary not only to have a good design, but also to improve the material properties used for engine parts. A valve seat insert is one of these parts that must be improved. High performance engines need a valve seat insert that has both wear resistance and heat resistance properties.