SINTERED FILTER HAVING STRAIGHT HOLES THERE-THROUGH AND METHOD OF MAKING SAME

摘要

1352419 Moulding filters TOYOTA CHUO KENKYUSHO KK 12 May 1971 [12 May 1970] 14585/71 Heading B5A [Also in Divisions C1 and C7] Sintered metal or ceramic filters are made by sintering a powder compact containing a series of parallel equi-spaced wires 11 which are fed from bobbins 12 through holes 131 of mesh 13 and anchored at mesh 15. The wires are thus located and supported in the cavity of a forming apparatus 16 in which a sintering powder is formed. The compact containing the wires is then sintered at a temperature sufficient to melt, burn or vaporize the wires. The sintering powder may be Fe, steel, stainless steel, W or W base alloys, Mo, Cr, Cr 3 C 2 , TiC, Al 2 O 3 or glass and the wires may be Cu, steel, Fe, Ni, Ni-Cr, rayon or glass fibres. Wire diameters may be 0À05-2 mm. and 10-1000 holes may be formed in the compact. The compact may be formed by any of the following methods: (a) slip casting a slurry 18 of Fe powder, ammonium alginate and water in plaster moulds 16 surrounding the wires as in Fig. 1. (b) Isostatically compacting the powder in a rubber mould containing the wires (Fig. 3, not shown). (c) Rolling the powder between rolls with the wires supported between the rolls (Fig. 4, not shown). (d) Lightly sintering the powder around the wires which are supported in a vertical furnace through which the powder is fed. Light sintering is at 700‹ C. for Fe powder with Cu wires. Where metal wires are used the metal infiltrates the compact during sintering.