公开(公告)号：US11125679B2

公开(公告)日：2021-09-21

申请号：US16929144

申请日：2020-07-15

Applicant: ROLLS-ROYCE plc

Inventor： James R. Fortune

IPC: G01N21/21 ,  G01J4/04 ,  G01N33/2045 ,  F01D21/00 ,  G01N21/95 ,  G01N21/88 ,  G01N21/84

Abstract: A method of analysing a component formed from a metal alloy to identify a possible defect, wherein the metal alloy comprises a first crystal grain region and the possible defect comprises a second crystal grain region aligned to a different axis to the first crystal grain region, the method comprising the steps of: obtaining a first image of the component illuminated using a first polarisation state of light, the first image comprising first polarisation data; obtaining a second image of the component illuminated using a second polarisation state of light different to the first polarisation state, the second image comprising second polarisation data; determining a difference in polarisation data for plural pixels of the first image between each pixel of the first image and a corresponding pixel of the second image; and identifying pixels corresponding to the second crystal grain region based on the difference in polarisation data.