| 摘要 |
PURPOSE:To obtain a preform having high bonding strength, causing no deformation and easy to handle by sticking polyaluminum chloride to reinforcing fibers and heating an aggregate of the fibers to convert the polyaluminum chloride into alumina hydrate and to bond the fibers to each other with the alumina hydrate. CONSTITUTION:Reinforcing fibers such as carbon fibers or boron fibers are passed through an aqueous soln. of polyaluminum chloride in the form of long fibers, short fibers, knit, a mat or the like to stick polyaluminum chloride to the reinforcing fibers, and an aggregate of the fibers is heated to a proper temp. and held to convert the stuck polyaluminum chloride into alumina hydrate or alumina. This alumina hydrate or alumina bonds the reinforcing fibers to each other chiefly at the intersecting points, forming a porous preform. This preform has high bonding strength, is easy to handle and hardly causes the migration of the reinforcing fibers when molten metal is impregnated into the preform. |
