| 摘要 |
<p>1291350 Hot pressing oxidic powders WHEELING-PITTSBURGH STEEL CORP 28 May 1970 [2 June 1969] 25790/70 Heading C1A [Also in Division C7] A method of hot pressing pulverulent oxides comprises packing a heated compact 12 of the oxide in refractory powder in a container 11, transferring the assembly above a die cavity 14 and discharging the compact and refractory powder into the die where it is compacted. The container and refractory powder may also be preheated. All the operations of precompaction, loading, heating and hot pressing may be effected in a controlled atmosphere, e.g. vacuum, He, A, H 2 , N 3 , NH 3 , CO or hydrocarbon gases and the apparatus is surrounded by enclosure 15. The heated precompact 12 may be sheathed in metal or ceramic which may be sprayed or cast on the compact. The powders may vary from less than 1 micron to 30 mesh and may be mixed with binders. The refractory packing powder, preferably of -100+325 mesh may be oxides, clays, sulphates, silicates, aluminates, CaF 2 , nitrides, carbides, silicides, borides, sulphides or carbon.</p> |
