| 摘要 |
<p>PURPOSE:To obtain a sintered metallic body having high dimensional accuracy by molding the kneaded plastic material composed of sinterable metallic powder and synthetic resin binder then enclosing the molding with a granular backup material, decomposing thermally the above-described binder in the molding and sintering the molding. CONSTITUTION:A synthetic resin binder is added to a powder mixture composed of, for example, self-fluxing Ni alloy powder and ground Mo powder at a prescribed ratio and is thoroughly kneaded to prepare the kneaded material which is then heated to 100- 150 deg.C to evaporate the moisture in the binder. The kneaded material is heated to 80- 100 deg.C and is passed plural times through a roll machine, by which a sheet-shaped plastic material is obtd. The sheet-like plastic material is molded to, for example, circular cylindrical molding and thereafter the molding is put in a case and is enclosed with steel balls as a granular backup material. Such molding is installed in a vacuum furnace. The molding enclosed with the steel balls is heated from an ordinary temp. up to 650 deg.C. The moisture is first evaporated, then the binder is gasified and removed by thermal decomposition during this time. The molding from which the binder is removed is heated to 900-1,000 deg.C and is heated to the temp. exceeding, for example, the liquidus line, for example, 1,000-1,200 deg.C after calcination, by which the sintered metallic body, i.e., the sintered Ni body is obtd.</p> |
