Quality control and enhancement of microwelds for Ir-192 sample holders

This study shows the micro quality results of tungsten inert gas welds on stainless steel AISI 304 of 5 sample holders for 30 discs by 3 mm diameter and 0.5 mm thick of Ir-192 sources produced in the Radioisotope Production Plant (RPP) of IPEN, generally used in industrial gammagraphy. Macrographic and conventional metallographic analysis were performed to measure the amplitude, thickness and centering parameters of the weld bead, centered data have helped to determine the parameters for welds with good quality, showing defects due to the misaligned glass lens, low magnification image and high visual angle of incidence across the 200 mm security leaded glass giving a low quality weld image due to the low magnification, large chromatic aberration resulting in a weld outside the seam, this problem was solved by changing the old optical visualization system by an external telescope specially designed for this purpose and raising the workbench so that the optical telescope axis and the weld are horizontally, achieving more rapid processes, reliable and reproducible, this new system has proved more convenient, reliable and reproducible. (authors).