Fantasy high temperature materials

76 Electron probe microanalysis Al composition profiles of three chemical vapor deposited (CVD) aluminide coated Fe-9Cr-1Mo samples as-deposited, after 2000 h at 700°C and after 2000 h at 800°C. Compared to the initial Al profile, significantly more Al interdiffusion occurred at 800°C than at 700°C. Results summarized from Zhang et al. (2004, 2007) and Pint et al. (2007e). 

A1 concentration was 10A1 after only 6kh at 800°C. Many power generation applications desire 40 kh minimum service lifetimes (Pint et al., 2006b). In addition to interdiffusion and its effect on substrate mechanical properties (Dryepondt et al, 2006), other coating compatibility problems must be addressed, such as the formation of undesirable phases and surface crack nucleation. Thus, the notion that coatings are universally available to protect non-oxidation resistant compositions is limited to short lifetime applications at best. 

77 The effect of oxygen uptake (i.e. internal oxidation) on the room temperature uniform and total elongation of Nb-IZr as well as on the yield and ultimate tensile strength. Results summarized from DiStefano and Chitwood (2001). 

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