| || Nondestructive Testing Method for Finding out the Defects in a Composite Liner
Author : George, Sheri ;Muralidhar, C.
Source : Defence Science Journal ; Vol:49(4) ; 1999 ; pp 339-342
Subject : 53 Applied Physics
Keywords : X ray radiography ;X ray computed tomography;Ultrasonic X ray radiography
Abstract : "A composite liner of carbon phenolic has been inspected by ultrasonic, X-ray radiography and X-ray computed tomography (CT) to find defects like delaminations, debonds, voids, foreign inclusions, etc. The geometry, detection of multiple defects and porosity of the liner make ultrasonic testing (pulse-echo and drycoupling) difficult for inspection. X-ray radiography being a non-contact technique finds multiple defects but compresses the structural information of 3-D volume into a 2-D image and interferes with overlying and underlying areas of the object. X-ray CT generates an image of a thin and cross-sectional slice of an object. The linear attenuation coefficients in terms of Hounsfield values have been measured, compared and correlated with CT images at the contrasts observed. 3-D images can be generated by stacking 2-D cross-sectional images of the slices. These 3-D images can be cut at any angle of choice for mapping the extent of delaminated/debonded areas. This type of information is difficult to obtain with conventional non-destructive testing techniques. "