Research on Total Focusing detecting of Titanium Alloy by Additive Manufacturing

Aiming at the additive manufacturing part by Electron Beam Rapid Manufacturing of TC4 (Ti-6Al-4V) titanium alloy, the research of total focusing detecting and imaging of internal small defects was carried out. Firstly, the CIVA software was used to simulate the sound field distribution with different transducer parameters, and the effect of the element center distance on the sound field was analyzed. Then, the total focusing method was used to detect the Φ0.4mm flat-bottom holes with buried depths between 3mm and 50mm. A high signal-to-noise ratio detecting method for this kind of structure was analyzed and summarized. The results show that, in a certain range, with the increase of the center distance of the array, the width and depth of the focal zone gradually decrease, and the resolution gradually increases. But at the same time, the energy of the sound field gradually disperses and the grating lobe phenomenon occurs; Olympus 10L64 linear array probe can be used to effectively detect the defects with a buried depth of 20mm-50mm, but the signal-to-noise ratio is relatively poor for the two cases with a buried depth of 3mm and 10mm, respectively. To overcome the disadvantage, a new transducer with smaller center distance is proved to be effective.