Method of measuring distribution of crystal grains in metal sheet and apparatus therefor
US4893510A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1988 |
| Grant date | Jan 16, 1990 |
| Priority date | — |
| Expiry date | Nov 14, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/044
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In measuring a distribution of crystal grains in metal sheet, an exciting frequency of ultrasonic wave is determined such that a wavelength of the ultrasonic wave propagated in a direction of the sheet thickness of the grains each having an aimed orientation is set at a value of twice the thickness of the sheet multiplied by about integers or about half integers, burst-like ultrasonic pulses having this frequency and including two or more waves are directed into the direction of the sheet thickness by use of an ultrasonic probe moving relatively with a body to be measured, multiple reflected waves generated from the bottom and top faces of the metal sheet upon the reflection from the sheet surface are caused to interfere with each other, the multiple reflected waves, which have interfered with each other, are detected, orientation of the grains in the metal sheet are estimated from the magnitudes in amplitude of the interferent multiple reflected waves thus detected, and the distribution of the grains in orientation in various portions, into which the ultrasonic wave is directed, is detected two-dimensionally.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.