Search Results

Materials with appropriate behavior at high temperatures and aggressive environments have become a scientific and technological necessity nowadays. Studies have been undertaken for improvement in getting new alloys, especially for the reevaluation of existing commercial alloys, through the acquisition of data under conditions of higher severity. In this context it was used for this work to Ti-6Al-4V in the form of cylindrical bars, provided forged and annealed at 190°C for 6 hours and cooled in air, which has favorable properties for aerospace application. The alloy after heat treatments to obtain the bimodal structures, martensite and Widmanstätten was subjected to creep tests at 600°C under the conditions of 250 and 319 MPa, in the form of constant load. The structures of Widmanstätten and martensite showed higher creep resistance in both stress conditions used in the trials.

An important energy source in commercial aircrafts is the high pressure, high temperature air that is bled from the engines and routed throughout the airframe to secondary systems. This hot air is transported by the engine bleed system, a set of thin-walled ducts whose reliability and durability are important for flight safety. Among the various materials suited for use in this system, titanium stands out because of its favorable characteristics, such as high strength-to-weight ratio and corrosion resistance. The effects of aging must be taken in account when predicting the useful life of the bleed system parts. In order to understand and describe the damage accumulation process suffered by the titanium ducts, a set of cyclic pressurization tests simulating the service conditions was conducted in a pneumatic workbench. Tensile and fatigue ring-shaped specimens were further cut from these ducts and tested in laboratory air at room temperature in a servo-hydraulic machine.