Agency for Defense Development

Poongsan Corporation

Joon Woong Noh

Seong Min Lee

Heung Sub Song

Woon Hyung Baek

Eun Pyo Kim

Moon Hee Hong

Kyung Jin Park

Moon L Hong

Kil S Churn

Young M Lee

A sintering method for a W--Ni--Mn type heavy alloy, including controlling the deoxidization of tungsten and nickel under an inert atmosphere, changing to a hydrogen atmosphere at above a temperature at which manganese is deoxidized and simultaneously deoxidizing tungsten, nickel and manganese, and sintering by raising the temperature, resulting in the fabrication of a sintered heavy alloy having a 100% relative theoretical density.

Sintering method for tungsten-nickel-manganese type heavy alloy

A fabrication method for a tungsten heavy alloy includes first fabricating a green compact or a sintered body composed of tungsten and other elements except manganese, then putting manganese thereon, and sintering the tungsten heavy alloy with manganese manganese, whereby the formation of pores, which occurs because manganese is oxidized by the deoxidation of oxides existing on the surface of powders of tungsten, nickel and iron is prevented, and a tungsten heavy alloy having a 100% non-theoretical density of 100% is obtained.

Fabrication method for tungsten heavy alloy

A method for producing an irregular tungsten/matrix interface in tungsten based heavy alloy is disclosed. The method involves a cyclic heat treatment and resintering at above liquidus temperature for tungsten heavy alloys consisting of 80 to 98 weight % tungsten and remainder of matrix phase. The sintered specimens are cyclically heat treated at above 1000.degree. C. and resintered at liquidus temperature of the matrix phase for one minute to 4 hours at a constant temperature.

Irregular shape change of tungsten/matrix interface in tungsten based

A method for heat-treatment of tungsten based alloys, capable of improving impact toughness while keeping tensile strength and elongation. The method comprises maintaining a sintered tungsten based alloy consisting of 86 to 99 weight % tungsten and the balance at least one selected from a group consisting of nickel, iron, copper, cobalt and molybdenum, at a temperature ranged from 950.degree. to 1,350.degree. C. for a maintenance time of one minute to 24 hours, quenching the sintered alloy in water or in oil, and repeating the maintaining and quenching steps.

Repeated sintering of tungsten based heavy alloys for improved impact

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Daejon, South Korea

Joon Woong Noh