Laser method of precision hole drilling
US4092515A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1977 |
| Grant date | May 30, 1978 |
| Priority date | — |
| Expiry date | Apr 7, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K26/382
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method for obtaining a hole in a workpiece essentially free of a recast layer and heat affected zone with laser radiation is disclosed. Pulses of laser radiation having durations comparable to the time required to vaporize workpiece material, typically less than ten nanoseconds, and power densities at the workpiece sufficient to produce vaporization, typically in excess of a billion watts per square centimeter, are interacted with a workpiece in an oxidizing environment to produce vaporization of workpiece material. The vapor reacts with the gas to produce a vapor oxide which does not adhere to the workpiece resulting in the absence of a recast laywer. A hole having a desired size and shape is obtained by interacting the pulses of radiation with the workpiece at a high rate of repetition, typically in excess of ten pulses per second, until a desired amount of material is removed. The pulse duration is less than the thermal reaction time of the material resulting in the absence of a heat affected zone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.