For decades engineers, scientists and aerospace enthusiasts have talked about the endless benefits of hypersonic travel (>6000km/h). Many of the challenges relating to aerodynamic vehicle design have been solved, however finding thermal protection systems (TPS) that can withstand sustained periods of aerodynamic heating above 2000degC remains a major hurdle. Similar materials challenges are found in the nuclear industry including proposed fusion and Gen IV reactor designs, with the additional challenge of managing radiation damage effects.
Finite Element Modelling (FEM) is routinely used for simulating in-service component performance. Accurate FEM simulations require reliable thermophysical data including thermal conductivity and specific heat ideally covering end-use service temperatures. In ultra-high temperature environments, coatings and substrate materials are usually in service under the influence of oxygen containing atmospheres and thus knowledge of oxidation kinetics for candidate materials is important for maximising component lifetime. In part 1 of the webinar series we will discuss how thermoanalytical techniques including Laser Flash Analysis (LFA), Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA) are helping scientists and engineers design longer lasting products for ultra-high temperature environments.
Ultra-high temperature structural materials often require the use of refractory coatings and/or composites to improve high temperature oxidation resistance. Selecting candidate ultra-high temperature materials that minimise residual stresses from thermal expansion mismatch between materials phases is very important for maximising structural integrity during service. High aerothermal heating rates, typically seen in hypersonic vehicles, accelerate the risk of thermal shock effects if mismatch effects are not properly considered. Thus, knowledge of the thermal expansion behaviour during the design phase becomes very important. Furthermore, the use of high-temperature dynamic mechanical analysis (HT-DMTA) can provide key information on the structural integrity of candidate materials under dynamic loading prior to launch. In part 2 of the webinar series we will discuss how thermomechanical testing techniques are helping scientists and engineers to risk minimise their ultra-high temperature components.