Method for making a valve-seat insert for internal combustion engines
US4734968A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 21, 1986 |
| Grant date | Apr 5, 1988 |
| Priority date | — |
| Expiry date | Nov 21, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12937
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A valve-seat insert for internal combustion engines comprises a double-layered, sintered alloy composed of a valve-seat layer on which a valve is seated, and a base layer integrated with the valve-seat layer and adapted to be seated in a cylinder head of an engine. The valve-seat layer is composed of a sintered alloy of a high heat resistance and a high wear resistance having a composition comprising, by weight, 4 to 8% Co, 0.6 to 1.5% Cr, 4 to 8% Mo, 1 to 3% Ni, 0.3 to 1.5% C, 0.2 to 0.6% Ca, and the balance of Fe and inevitable impurities, the additives, Co, Cr and Mo being present mainly in a form of a Co-Cr-Mo hard alloy and a hard Fe-Mo alloy dispersed in the Fe matrix. The base layer is composed of a sintered alloy of a higher heat resistance and a higher creep resistance than those of the valve-seat layer and having a composition comprising, by weight, 11 to 15% Cr, 0.4 to 2.0% Mo, 0.05 to 0.3% C, and the balance of Fe and inevitable impurities. At least the valve-seat layer of the double-layered, sintered alloy is being fusion-infiltrated with copper.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.