| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a filter having excellent thermal impact resistance and corrosion resistance by interposing the filter of a cylindrical three-dimensional network skeleton structure having internal open cells into a passage where molten metal is poured from a sprue into a cavity. SOLUTION: A filter body is obtd. by adhering a ceramic slurry to a synthetic resin foam having no cellular films and firing the same, thereby carbonizing away the synthetic resin foam by firing and is formed of ceramics of >=1,000 deg.C in m.p. or sublimation point. The bulk sp. gr. thereof is 0.3 to 0.8, the number of pores per straight line 2.5 cm is 3 to 40 pieces and the void volume is >=65%. The molten metal flows through the inside of a sprue rod 21 and a runner 22 from the spure 20, into an annular molten metal path 30 and flows through the three-dimensional internal spaces from the outer side of the peripheral wall part 11 of the filter body 10, by which impurities in the molten metal are removed. The molten metal subjected to the filtration flows into the hollow part 12 of the filter body 10 and flows to the mold cavity. The molten metal is thus filtered rapidly with good efficiency while the fluidity thereof is improved.</p> |
