D.A.Davydov,** M.I.Solonin, Yu.E.Markuchkin, V.A.Gorokhov, V.V.Gorlevsky
National Scientific Center of Russian Federation
A.A.Bochvar All-Russian Scientific Research Institute of Inorganic Materials
( VNIINM ), 123060 Moscow, P.Box 369, Russia, tel. ( 095 ) 190 - 8085, fax
( 095 ) 196 - 6671, E-mail: postmaster @ vniinm402.msk.su
sav@bochvar.ru
It is assumed that the porous beryllium will be used for the beryllium multiplier zones of the ITER breeding blanket. In the present report the preliminary results on fabrication technique and properties of porous beryllium are described.
The technique comprises several successive stages, including a preparing of mixture of beryllium powder and beryllium hydride and manufacturing of beryllium mock-up with 15 % porosity.
Using the manufacturing procedure the porous beryllium mock-up in a SS shell with 2 mm wall thickness was fabricated.
Measurements and calculations have shown that the average porosity of the mock-up is near 15 %. The results indicate that all the samples have the guaranteed open porosity.
The mechanical properties as averaged based on the results of two to three tests for each porosity are: for compression tests - 798 MPa and e = 3.9 % ( for the 12.36 % sample porosity ) and 412 MPa and e = 2.4 % ( for the 20.56 % sample porosity ); for tensile tests - 19 MPa and d = 0 ( for the 18.36 % sample porosity ) and 72 MPa and d = 0.8 % ( for the 12.0 % sample porosity ).
The mean thermal expansion coefficient ( TEC ) for the two temperature ranges ( a20-400 C and a20-800 C ( 1 / C ) is: (14.7 ± 0.5 - 17.6 ± 0.5 )´ 10-6. .
The measured thermal conductivity values were 80±10 W / ( m K ) for the 18.69 % sample porosity and 120±10 W / ( m K ) for the 13.0 % sample porosity.
Preliminary findings:
1. The scrap - free technique has been designed for porous beryllium items having the specified porosity.
2. The porosity of the item is inherently open.
* Work supported by the ITER JCT
** D.A.Davydov, 123060 Moscow, P. Box 369, VNIINM, Russia