Benefits of Aeronautical Preform Manufacturing through Arc-Directed Energy Deposition Manufacturing.

The paper introduces an innovative aerospace component production approach employing Wire Arc Additive Manufacturing (WAAM) technology to fabricate near-finished preforms from Ti6Al4V titanium. Tensile tests on WAAM Ti6Al4V workpieces demonstrated reliable mechanical properties, albeit with identified anisotropic behavior in horizontal samples, underscoring the need for optimization. This alternative manufacturing strategy addresses the challenges associated with machining forged preforms, marked by a high Buy To Fly (BTF) ratio (>10), leading to material wastage, prolonged machining durations, elevated tool expenses, and heightened waste and energy consumption. Additionally, logistical and storage costs are increased due to extended delivery timelines, exacerbated by supply issues related to the current unstable situation. The utilization of WAAM significantly mitigates initial BTF, preform costs, waste production, machining durations, and associated expenditures, while notably reducing lead times from months to mere hours. The novelty in this study lies in the application of Wire Arc Additive Manufacturing (WAAM) technology for the fabrication of titanium aircraft components. This approach includes a unique height compensation strategy and the implementation of various deposition strategies, such as single-seam, overlapping, and oscillating.

Anesthetic Implications of Previously Undiagnosed Temporomandibular Joint Ankylosis: A Case Report.

Temporomandibular joint (TMJ) ankylosis is characterized by bony fusion that limits TMJ mobility. We present the case of an elderly woman who was brought to the operating room for dental rehabilitation under general anesthesia. The patient had an undiagnosed TMJ ankylosis, which was discovered only after induction of anesthesia due to her nonverbal status and advanced dementia. The surgical team canceled the case due to limited access to the surgical field. We discuss the factors that suggest TMJ ankylosis and propose the perioperative management when TMJ ankylosis is suspected but unconfirmed.

Wall Fabrication by Direct Energy Deposition (DED) Combining Mild Steel (ER70) and Stainless Steel (SS 316L): Microstructure and Mechanical Properties.

Direct energy deposition is gaining much visibility in research as one of the most adaptable additive manufacturing technologies for industry due to its ease of application and high deposition rates. The possibility of combining these materials to obtain parts with variable mechanical properties is an important task to be studied. The combination of two types of steel, mild steel ER70-6 and stainless steel SS 316L, for the fabrication of a wall by direct energy deposition was studied for this paper. The separate fabrication of these two materials was studied for the microstructurally flawless fabrication of bimetallic walls. As a result of the application of superimposed and overlapped strategies, two walls were fabricated and the microstructure, mechanical properties and hardness of the resulting walls are analyzed. The walls obtained with both strategies present dissimilar regions; the hardness where the most present material is ER70-6 is around 380 HV, and for SS 316L, it is around 180 HV. The average values of ultimate tensile strength (UTS) are 869 and 628 MPa, yield strength (YS) are 584 and 389 MPa and elongation at break are 20% and 36%, respectively, in the cases where we have more ER70-6 in the sample than SS 316L. This indicates an important relationship between the distribution of the materials and their mechanical behavior.

Development and tests of a paediatric and neonatal immobilizer for ambulance transfers.

There are many stretcher models able to adequately achieve the spinal immobilization of adult patients during emergency transports but do not work well with children. A paediatric and neonatal immobilizer has been designed, constructed and tested. It is simple, radio-transparent, able to be adequately fastened to an ambulance, adaptable to a wide range of paediatric patient's size, providing a correct spinal immobilization without an excessive immobilization of the rest of the body, without impairing the aperture of an aerial way or the cardiopulmonary resuscitation (CPR) and without reducing the accessibility of the medical personnel to the paediatric patient. It is able to be adapted to the size and injuries of the patient instead of adapting the position of the patient to the characteristics of the immobilizer. It can also be effectively fastened to the bed of an emergency helicopter, allowing the aerial transport of the paediatric patients.