Method and apparatus for manufacturing structures with improved fatigue life
US6742376B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 2001 |
| Grant date | Jun 1, 2004 |
| Priority date | — |
| Expiry date | Feb 9, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2221/00
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A compound indenter for metal coldwork, and a method of employing such tooling. The compound indenter tool is used to produce deformation in a workpiece structure, to provide a selected beneficial residual stress profile in the workpiece, in order to provide high fatigue life structures in a minimum number of manufacturing steps. Preferably, action of a compound indenter causes deformation of the workpiece, causing dimples in the workpiece. By optimized use of the method, a relatively uniform beneficial residual stress profile is provided at both the surface and at the midplane apertures in a workpiece, so as to improve overall fatigue life. An improved, compound indenter tool profile shape is described, having a first, elongate indenter with a shaped indenter surface portion, and a second shaped indenter surrounding the first indenter and forming an annular shoulder recessed from the surface portion of the first indenter. Additionally, a foot having a bottom portion can be used to confiningly surround the second indenter during application of force to the surface of a workpiece, to prevent surface deformation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.