Fig. 14. Time MLN2238 of temperature in the powder center of a) a 2.83 mm pellet and b) for a 0.5 mm coating on a 2.0 mm substrate, for a 1 s long combustion for gap conductivities of 0, 1E4, 3E4, 1E5 and 1E9 W/(m2 · K), counting from top to bottom.Figure optionsDownload full-size imageDownload high-quality image (351 K)Download as PowerPoint slide
Comparing Fig. 14a and b, it is evident that the maximum temperature is much reduced by the introduction of a substrate and the reduction of powder height, 0.5 instead of 2.83 mm.
It could be emphasized that the simulations in Fig. 14 were made using the “time dependent study” of Comsol Multiphysics restricting the time step to max 0.01 s. This limitation is very important for the solver not to miss any phase transitions.
From the SPS-experiments termination codon is known that powder heights of 2.83 and 0.5 mm correspond to powder charges of 1.7 and 0.3 g, respectively. As a result, the reaction enthalpy was adjusted to these masses.