摘要:
Xylylene diisocyanate is produced in higher space-time yield with higher selectivity by thermal decomposition of xylylene dicarbamate as an urethane compound, i.e. by subjecting the urethane compound to reactive distillation with a thermal decomposition catalyst of at least one of metals selected from antimony and tin or their compounds in the presence of an inert solvent having a higher boiling point than that of the resulting xylylene diisocyanate under reduced pressure of 1 to 500 mmHg and at 150.degree. to 350.degree. C. and then subjecting the resulting reaction products as distillates to partial condensation outside the reactive distillation system, thereby separately recovering the resulting alcohol and xylylene diisocyanate.
摘要:
A die casting machine for manufacturing impellers made of Ni-, Co- or Fe-based heat resistant alloys. A die assembly which is provided with a plurality of radially retractable segments, is coaxially arranged and vertically movable with respect to an injection assembly. Die casting is effected in the lowermost position of the die assembly with the segments closed. The product is ejected out of the machine in the uppermost position of the die assembly with the segments retracted. A short runner minimizes heat dissipation of the molten metal and improves uniformity and quality of the product.
摘要:
A heat-resisting aluminum alloy contains manganese ranging from 6 to 8% by weight, iron ranging from 0.5 to 2% by weight, zirconium ranging from 0.03 to 0.5% by weight, and copper ranging from 2 to 5% by weight, the balance being essentially aluminum. The aluminum alloy has been confirmed to be high in mechanical strength both at ordinary temperatures and at high temperatures while to be suitable for producing an article by using so-called atomization process.
摘要:
A sintered ferrous alloy which is high in wear resistance and relatively weak in the tendency to abrade another metal material with which the sintered alloy makes rubbing contact. The sintered alloy is produced by compacting and sintering 100 parts by weight of a powder mixture of 5-35 parts by weight of a Fe-Cr-B-Si alloy powder, which contains 10-35% of Cr, 1.0-2.5% of B and 0.5-3.0% of Si, such an amount of a Cu-P alloy powder that the powder mixture contains 0.2-1.5% of P and 1.0 to 20.0% of Cu, and the balance of a cast iron powder. Preferably the cast iron powder contains 2.5-3.5% of C, 1.8-2.2% of Si and 0.6-1.0% of Mn. For example, the sintered alloy is suitable for rocker arm tips in automotive engines.
摘要:
A method for joining a member to a diecast article using an apparatus comprising dies, an injection sleeve communicating with a cavity of the dies and a plunger tip slidably arranged in the injection sleeve for filling the cavity of the dies with the molten metal previously poured in the injection sleeve. According to the invention, the plunger tip is formed with an insert aperture for receiving the member to be joined such that a portion of the member extending beyond an upper surface of the plunger tip is exposed in the molten metal when it is poured in the injection sleeve, thereby sufficiently transmitting the heat of the molten metal to the portion of the member to obtain a metallurgical bond at a boundary between the member and the diecast article.
摘要:
A method for joining a porous metallic member and a non-porous metallic member includes by passage of an electric current after forming a dense portion on a joining surface of the porous metallic member by caving a projection provided on a joining surface of the non-porous metallic member into said porous metallic member whereby both metallic members are joined firmly without using screws or adhesives.