It is less effective in detecting planar defects like cracks that are usually the most critical type of defect in welds, unless it is appropriately oriented to the radiation source. Based on X-Ray or neutron absorption, it strongly depends on the mass of the material and is precise in detecting volumetric defects related to both extra and missing material 4. Radiographic inspection is widely used for weld inspection. Further, the inspection technique should be performed rapidly and preferably during the welding (in process inspection), to not become the bottleneck of the process. However, the use of welded structures on airframes demands a qualified and robust welding process, including a reliable defect control system, based on NDI techniques. For aircraft manufacturing, for example, the weldable Al-Mg-Si-Cu alloy has been used for fuselage applications substituting the conventional riveted structure 1-3. Those characteristics are attractive for both automotive and aerospace industries. The high concentrated energy (around 10 6 W.cm -2) in a precision controlled spot enables welding in key-hole mode, at welding speeds up to 10 m/min in thin sheets, resulting in a very narrow heat affected zone. Laser beam welding (LBW) is an attractive joining process for aluminum structures, due to its high production rate, associated with high quality welds. Keywords: ultrasonic inspection, pulse/echo phased array, laser welding, aluminum alloy This attenuation is attributed to the scattering of the waves caused by micro pores, with individual size below the resolution limit of the equipment, but when grouped, can cause a perceptive effect on the reflection spectra. The results showed that ultrasonic phased array technique was able to identify the presence of grouped porosity, through the attenuation of the amplitude of the echo signal. Good and poor quality welds were inspected in order to verify the limits of inspection, comparing also to X-ray radiography and metallographic inspections. In this work, bead on plate laser welds on 1.6 mm thick AA6013 alloy sheets, using a 2 kW Yb-fiber laser were obtained and inspected by pulse/echo ultrasonic phased-array technique. The joints quality is usually assessed by non-destructive inspection (NDI). Interest in laser beam welding for aerospace applications is continuously growing, mainly for aluminum alloys. IIIDepartamento de Ciência e Tecnologia, Universidade Federal de São Paulo - UNIFESP, Rua Talim 330, CEP 12231-380, São José dos Campos, SP, Brazil IIDivisão de Fotônica, Instituto de Estudos Avançados - IEAv, CEP 12228-001, São José dos Campos, SP, Brazil Brigadeiro Faria Lima 2170, CEP 12227-901, São José dos Campos, SP, Brazil Ultrasonic inspection of AA6013 laser welded jointsĪdriano Passini I Aline Capella de Oliveira II Rudimar Riva II Dilermando Nagle TravessaIII, * Kátia Regina Cardoso III
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |