Shrinkage porosity defect is the key research object of this project. The observation method for this defect is fluorescence penetration method. Its principle is to irradiate the sample surface treated by fluorescent agent, and the penetrant entering into the hole area of the sample surface through penetration will show white color, and the fluorescent agent model is zl60d.
(1) The surface of the sample to be measured is roughened;
(2) Rinse the sample surface with water and dry it;
(3) Apply the fluorescent agent evenly on the surface to be tested and keep still for 3-5 minutes
(4) Observe the surface to be tested of the treated sample under ultraviolet light and take photos. Finally, the fluorescence test results of the treated sample are shown in the figure