Abstract: This invention provides a method of forming a powder compact which can produce a high density compact under a high pressure and at the same time can reduce pressure for ejecting the compact from a die. This method comprises the application step of applying a higher fatty acid lubricant to an inner surface of a heated die, and the compaction step of filling metal powder into the die and compacting the metal powder under such a pressure as to force the higher fatty acid lubricant to be chemically bonded with the metal powder and form a metallic soap coating. Since the metallic soap coating is formed between the die and a compact, friction force between the die and the compact is decreased and ejecting pressure can be remarkably decreased despite of compaction with high pressure. Besides, a high density compact can be obtained owing to the compaction with high pressure.

Abstract: The present invention is characterized in that, in a powder magnetic core obtained by compaction of an iron-based magnetic powder covered with an insulation film, a saturation magnetization Ms is Ms?1.9 T in a 1.6 MA/m magnetic field; a specific resistance ? is ??1.5 ??m; a magnetic flux density B2k is B2k?1.1 T in a 2 kA/m magnetic field; and a magnetic flux density B10k is B10k?1.6 T in a 10 kA/m magnetic field. In accordance with the present invention, it has been possible to industrially carry out compacting iron-based magnetic powders under remarkably high compacting pressures. As a result, high-performance powder magnetic cores are obtained which have a high density, and which are good in terms of the specific resistance and magnetic permeability.

Abstract: The present invention is characterized in that, in a powder magnetic core obtained by compaction of an iron-based magnetic powder covered with an insulation film, a saturation magnetization Ms is Ms≧1.9 T in a 1.6 MA/m magnetic field; a specific resistance &rgr; is &rgr;≧1.5 &mgr;&OHgr;m; a magnetic flux density B2k is B2k≧1.1 T in a 2 kA/m magnetic field; and a magnetic flux density B10k is B10k≧1.6 T in a 10 kA/m magnetic field. In accordance with the present invention, it has been possible to industrially carry out compacting iron-based magnetic powders under remarkably high compacting pressures. As a result, high-performance powder magnetic cores are obtained which have a high density, and which are good in terms of the specific resistance and magnetic permeability.

Abstract: A magnesium alloy having excellent castability and creep properties has compositions of 1.0-6.0 wt % Zn, 0.5-3.0 wt % Ca, 1.0 wt % or less Zr, 1.0-5.0 wt % at least one lanthanoid, the remainder being Mg and unavoidable impurities. This magnesium alloy undergoes heat treatment of heating the magnesium alloy to 430-470 ° C., quenching, and then heating to 150-250 ° C. for aging. Hot tearing and temperature strength are improved by the addition of an element which is effective for causing eutectic reaction and peritectic reaction with Mg and making Mg particles divied finely.

Abstract: This invention provides a method of forming a powder compact which can produce a high density compact under a high pressure and at the same time can reduce pressure for ejecting the compact from a die.

Abstract: A ferritic heat-resistant cast steel includes C in an amount of from 0.1 to 0.4% by weight, Si in an amount of from 0.5 to 2.0% by weight, Mn in an amount of 1.0% by weight or less, S in an amount of from 0.06 to 0.20% by weight, Ni in an amount of 1.0% by weight or less, Cr in an amount of from 13 to 20% by weight, V in an amount of from 0.2 to 1.0% by weight, at least one element selected from the group consisting of Nb in an amount of from 0.1 to 0.4% by weight, Mo in an amount of from 0.1 to 2.0% by weight, and W in an amount of from 0.2 to 4.0% by weight, and the balance of Fe and inevitable impurities, the S being dispersed as sulfides in the ferritic heat-resistant cast steel. It can further include at least one element selected from the group consisting of Te in an amount of from 0.01 to 0.1% by weight and Al in an amount of from 0.01 to 0.5% by weight. It can be produced by melting and casting the alloying elements and thereafter by annealing the resulting cast product at a temperature of from 750.

Abstract: Disclosed are an aluminum alloy casting having a high strength and a high toughness, and a production process for the same. The aluminum alloy casting comprises silicon (Si) in an amount of 2.5 to 4.4% by weight, copper (Cu) in an amount of 1.5 to 2.5% by weight, magnesium (Mg) in an amount of 0.2 to 0.5% by weight and the balance of aluminum (Al), and a matrix thereof includes a dendrite which has a size of 30 micrometers or less. Since the Si addition amount is suppressed as less as possible and since the size of the dendrite is micro-fined in the aluminum alloy casting, the toughness is improved remarkably. Further, since the Cu and Mg are added in the predetermined addition amounts, the strength is enhanced in the aluminum alloy casting. In addition, a solution treatment which is employed in the production process can further enhance the strength of the aluminum alloy casting.

Abstract: A method for producing aluminum alloy castings and the resulting product having improved toughness. An Al-Si or Al-Si-Cu alloy containing 4 to 24 wt % of silicon, iron and other incidental impurities, the balance being aluminum is melted, and the melt is heated to a temperature between 780.degree. C. and 950.degree. C. The melt is poured into a mold and there solidified. A solution heat treatment and aging are then conducted. The process is suitable for an alloy containing 0.25 to 1.4 wt % of iron. In a preferred embodiment, the alloy consists essentially of 6 to 12 wt % Si, 2 wt % Cu, 0.2 to 0.4 wt % Mg and other incidental impurities, the balance being aluminum. The solution heat treatment is preferably carried out by heating between 525.degree. 545.degree. C. for a period of 1 to 5 hours.