Rapid and sensitive radioscopy for fine ceramics using an image-subtraction method

A new microfocus X-ray testing method has been developed to detect very sma ll defects in ceramic products with high speed and reliability. By using im age subtraction, enhanced X-ray images of defects were extracted from the b ackground noise. Much-better sensitivity (e.g., 0.1% in Si3N4 that was 20 m m thick) was obtained within a few minutes. This method is considerably sup erior to the conventional film method. In this study, Si3N4 test pieces (pe netrameters) that had very small artificial defects (such as slits and pore s) were prepared and examined by using the new method.