Development of High Performance Valve Seat Insert Materials for Heavy-duty Engines 2006-01-0394
Sintered materials have been applied widely for Valve Seat Inserts (VSI) due to their high flexibility of material design. Hard particle dispersion type materials, which have specific microstructures in sintered material, are popular for VSIs.
The load - temperature, combustion pressure, etc. - on the VSI has become severer along with increasing demands for better engine performance. (1) Especially, there is increasing tendency of the amount of wear on VSIs when used in heavy-duty engines such as diesel/gas (LPG, CNG) engines because of their dry environments.(2)
In this paper, two new developed high performance VSI materials for heavy-duty engines are introduced. These materials adopt new hard particles and a new method of distribution of the solid lubricant to increase wear resistance.
Hard Particles: The new developed hard particle has superior wear resistance due to increasing the amount of intermetallic compounds.
Lubrication: A new method has been developed that has superior lubrication by distributing the lubricant in the matrix using precipitation during sintering.