关键词: |
Additive manufacturing, Electron beam melting, Computer-aided design, Image processing, Surface roughness, Ultrasonic inspection, Titanium alloys, Aircraft equipment, Background noise, Aerospace industry, Fabrication, Nondestructive inspection, Ultrasonic testing |
摘要: |
Further research on validating additive manufacturing production quality is required before the realization of direct print-to-fly application of critical components. This research examines the response of ultrasonic testing as a function of various manufacturing variables in electron beam melted samples of Ti-6Al-4V. Four dimensionally identical blocks with 6 spherical voids at varying depths were manufactured using different combinations of stock powder, edge treatments, and void melting. Scans were completed on two sides of each specimen with the transducer focused on the mid-plane. Additionally, one specimen was scanned 6 times, with the focal plane adjusted for each scan to match the depth of each void. Image processing techniques were then used to analyze each scan. Scans along the build layers with all voids in plane with the transducer's focus identified the most voids while scans through the build layers were more difficult to identify. However, back wall returns increased the probability of detection. Overall, powder selection had the greatest influence on image quality and detection success, while other modes had significantly lower effects. |