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.
Several years ago, we developed a double layer valve seat insert by P/M process for high performance diesel engines and have actually utilized it in diesel engines.
In prototypes of the neWly developed engines, the insert lacked sufficient wear resistance and heat resistance.
Therefore, we have started to develop a liquid phase sintered valve seat insert. The following are some experimental results relating to these properties.