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Comprehensive knowledge of the complicated physical behavior of the induction furnace with cold crucible (IFCC) is required to utilize the advantages of this melting aggregate in melting and casting chemically high-reactive materials, like titanium-aluminides (TiAl). Practical experiences show that the overheating temperature of the melt is decisive for the quality of the cast products. Therefore, a systematic analysis of the electromagnetic and in particular, the hydrodynamic and thermal behavior of the IFCC is carried out. The examinations of the influence of the construction elements as well as the process parameters on the temperature field and finally the overheating temperature in the IFCC are performed using specifically developed numerical models. The evaluation of the numerical results is done by experimental investigations, where aluminum serves as a model melt for the experimental determination of the thermal and hydrodynamic field of the melt. The analysis of the influence of construction-elements on the overheating temperature is focused on the design of the crucible wall and the crucible bottom, on the height-diameter ratio of the crucible and on the axial inductor position. The inductor current, the operation frequency and the crucible filling level are found to be very important for reaching a high overheating temperature.

Demands for reduced maintenance, reduced manning and reduced cost are resulting in the need for new and alternative materials for introduction in the fleet. The new materials in many cases tend to be non-metallic and organic (combustible) materials. In order to maintain a minimum level of fire safety, the US Navy has set performance requirements for new materials in many applications. These include the use of composite materials in ships and submarines. Performance requirements for composites, in most cases, are based on full-scale fire tests. The use of composites for structural applications in submarines is covered by MIL-STD-2031. The use of composites aboard US Navy ships for topside applications is now covered by Fire Safety testing criteria. The recommended fire performance criteria contain requirements for fire growth, smoke toxicity, visibility (ISO 9705), fire resistance and structural integrity under fire (UL 1709). When developing new composite systems, it is expensive to repeatedly conduct these typical full-scale fire tests to determine the performance of the most recent design. Instead, more costeffective small-scale testing is preferable to evaluate performance. To facilitate the introduction of new and modified fire tolerant materials/systems/designs, and to reduce the financial burden on small business, the US Navy has developed a low cost composite system fire screening protocol which offers the potential of predicting the full-scale fire performance. Fire growth potential of new composite systems and designs can be screened by using small-scale test data from cone calorimeter (ASTM E-1354) and Lateral Ignition Flame spread Test (ASTM E-1321) in conjunction with the Composite Fire Hazard Analysis Tool (CFHAT). The small-scale burn-through test (2 Â 2 ft) was shown capable of screening fire resistance performance determined in furnace testing with a UL-1709 fire curve. These screening techniques provide cost-effective approaches for evaluating fire performance of new technologies, which in turn aids in the product development process. Full-scale fire testing is still required before inclusion of products onboard US Navy submarines and surface ships. Published in

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