Wire Arc Additive Manufacturing (WAAM) is revolutionizing the field of Additive Manufacturing (AM) by being the technological solution to manufacture thin-walled structures of large dimensions and medium geometric complexity at reduced cost with an excellent buy-to-fly ratio. Manufacturing parts with this technology is nowadays done through 2.5D strategies. This type of strategy consists in cutting a 3D model using planar layers parallel to each other. This 2.5D technique limits the complexity of the geometries that can be produced in WAAM without taking advantage of height deposit modulation. It also requires several start/stop phases of the arc during the transition from one layer to another, which leads to poor quality. This paper presents a new fast and efficient path planning strategy aiming at creating a continuous manufacturing path, thus increasing poor part quality. This strategy so called "Scalar Thermal Field for Continuous Toolpath" is generating a continuous spiral manufacturing toolpath for thin shaped parts. The modulation of deposition, by controlling the welding torch travel speed at constant wire feed rate, allows continuous deposition of material throughout the manufacturing process. The keypoint of the method is the use of a thermal scalar field associated with a 6-axis robotic arm kinematics which allows the manufacturing of closed parts after optimal closure point determination or direct manufacturing of opened parts with non-planar free edges. Validation of the presented method is performed by manufacturing three distinct parts : an opened, a closed part and a multi-branch part. The fabrication of these parts and their precise measurement have shown the reliability and the restitution capacity of our method which is clearly superior to 2.5D strategies nowadays commonly used in WAAM technology.

Pellets are spherical agglomerated particles used to produce multiparticulate pharmaceutical dosage forms. This study aims to develop a new approach that evaluates the deformation behavior of pellets under compression, by combining tableting data and compression models with X-ray micro computed tomography (XMT) image analysis. The deformation of Microcrystalline cellulose (MCC) and sugar pellets known to have different deformation behavior under compression was investigated. Compression data and modeling confirmed the plastic and brittle behavior for MCC and sugar pellets respectively. Image analysis of the XMT showed a different evolution of the morphometric parameters: structure thickness diameter (St Th) and volume equivalent sphere diameter (ESDv). The brittle sugar pellets showed a decrease in both ESDv and St Th parameters while plastic MCC pellets showed a decrease in ST Th and a constant ESDv which is coherent with ductile and brittle material deformation. This study shows that XMT can be used as a tool to characterize the mechanical behavior of pellet particles during compression

The paper presents the impact of thermal cycling frequency on the lifetime of IGBT power module. The first part will be devoted to a quick presentation of the test bench. Then, the test protocols will be detailed as well as the measurement protocol to characterise the ageing of the power module wirebonds. An important part will be devoted to the results of ageing. Before concluding, mechanical tensile tests on bondwires will complete the ageing tests.