Iron aluminum based engine intake valves and its manufacturing method
US5425821A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1994 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | May 13, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49311
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention resides in a method for making an internal combustion engine intake valve. An iron aluminum alloy, in the form of a coil or bar stock, is provided. The alloy comprises 76.05 to 90.15 weight percent iron, 9 to 13.3 weight percent aluminum, 0.05 to 0.35 weight percent carbon, and 0.5 to 3 weight percent of a refractory metal, and/or 0.3 to 1.5 weight percent of titanium in combination with, or in place of, the refractory metal. The coil or bar stock is extruded to a poppet valve preform configuration at a heading temperature in the range of 800.degree. to 2,000.degree. F. and a true strain of about 0.5 to 2.2. The preform configuration is then headed to a pre-machined configuration while maintaining the head of such preform at an effective heading temperature up to 2,200.degree. F. said heading being carried out at a true strain of about 1.4 to 2.3. The headed preform is then machined, to its machined configuration, without intermediate heat treatment, and then is coated by either nitriding or chrome plating. If desired, a hardenable steel tip can be welded to the valve stem, and then heat hardened.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.