R. Vassen et al., POTENTIAL OF NANOCRYSTALLINE LOW-Z MATERIALS FOR PLASMA-FACING, STRUCTURAL APPLICATIONS IN FUSION-REACTORS, Journal of nuclear materials, 237, 1996, pp. 708-712
Citations number
15
Categorie Soggetti
Nuclear Sciences & Tecnology","Mining & Mineral Processing","Material Science
Several types of silicon based nanocomposite ceramics have been produc
ed by hot isostatic pressing (HIP) mixtures of ultrafine SIG, CSiC and
SiSiC powders (particle size below 50 nm) with conventional carbon, b
oron carbide or silicon carbide powders. Compared to pressureless sint
ering grain growth was substantially reduced by this technique. Sample
s have been characterized with respect to microstructure. Thermal cond
uctivity measurements at room temperature indicate a reduction of ther
mal conductivity compared to conventional materials. High heat flux ex
periments in the electron beam test facility JUDITH (Juelich divertor
test equipment in hot cells) with energy densities up to 11 MJ/m(2) ha
ve been performed. Although the thermal conductivity is relatively low
the materials prepared from SiSiC/C-mixtures show lower erosion rates
compared to conventional composites. The negative effect of low therm
al conductivity on thermal shock resistance seems to be overcompensate
d by the microstructural improvements in the nanocomposite materials.
A model, which calculates the erosion rates and takes account of micro
structural features like chemical composition and grain size, is prese
nted.