Spark plug
US12027826B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 24, 2022 |
| Grant date | Jul 2, 2024 |
| Priority date | — |
| Expiry date | Oct 24, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/32
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spark plug having a firing pad with minimal silicon diffusion and limited silicon oxidation at grain boundaries that can cause undesirable vertical cracking. In one embodiment, the firing pad has a multilayer structure having a base layer and a firing layer, wherein the base layer is a non-precious metal based material having silicon, and wherein the firing layer is a precious metal based material having yttrium in an amount of 0.1 to 0.5 wt %, inclusive. After at least 190 hours of isothermal treatment of at least 1000° C., an extent of vertical cracking from the sparking surface does not exceed 50% of a thickness of the firing pad or the firing layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.