| 摘要 |
1,208,148. Casting composite articles. E. I. DU PONT DE NEMOURS & CO. 21 June, 1968 [23 June, 1967], No. 29785/68. Heading B3F. [Also in Divisions C1, F1 and F2] A composite structure, such as an engine exhaust manifold or silencer, comprises a hollow ceramic core 2 having a compressive strength between 200 and 6000 p.s.i. and a metal casing 6 cast around it, the face 4 of the core being crushable to accommodate shrinking of the metal and facilitating mechanical bonding between the metal and the core by having, to a depth of at least 100 microns, a porosity of between 20% and 80% created by pores ranging in size substantially from 25 to 2500 microns. Several ceramic materials such as alumina, spinel, mullite, zirconia and berides, nitrides and carbides are specified. The cast metal 6 may be Ag, Al, Cu, Mg, Pb, Sn, Zn, white cast iron, grey iron, steel, brass, bronze or alloys or refractory metals. |
