Korea Institute of Science and Technology

Korea Advanced Institute of Science and Technology

Ju Choi

Myoung Ki Yoo

Jong Ku Park

Young Do Kim

Kyung Tae Hong

Seung Ick Lee

Seung Woo Lee

Chong K Lee

Hyon T Kim

A method for fabricating a hermetically sealed tungsten-copper package container for a microwave device is provided with the steps of forming an injection feedstock by mixing a polymer binder with a tungsten powder having a particle diameter of 2 to 5 .mu.m and a purity 99.9 of weight percent, forming a three-dimensional part by applying a powder injection molding to the feedstock, obtaining a tungsten skeleton structure by eliminating the binder from the injection molded part, and carrying out a copper infiltration to a copper plate placed on the tungsten skeleton structure for two hours under a hydrogen atmosphere at a temperature of 1250.degree. C. The method incorporates an improved heat sink characteristic, a thermal expansion coefficient similar to that of GaAs, and a capability of applying thereto a strip wire connection, without an extra machining process.

Hermetically sealed tungsten-copper composite package container for

A tungsten skeleton structure fabrication method employed in an application of a copper infiltration and tungsten-copper composite fabrication method includes the steps of forming a source powder by coating the tungsten powder surface having a purity of 99.9 weight percent and 2.about.5 .mu.m in size, with nickel by less than 0.06 weight percent (600 ppm), forming an injection molded admixture by admixing a source powder and a polymer binder, carrying out a powder injection molded with regard to the admixture, and obtaining a tungsten skeleton structure by removing the polymer binder from the resultant injection molded body. The method prevents the molded body from being unevenly shrunken during a liquid phase sintering for thereby decreasing its production cost.

Tungsten skeleton structure fabrication method employed in application

A fabrication method for a molybdenum disilicide sintered body in which a molybdenum disilicide powder having excellent oxidation resistance is sintered in a low-temperature sintering method and compacted at a low temperature and under no pressure, includes carrying out a milling on a molybdenum disilicide powder at a low temperature, providing a diffusion path required to sinter the molybdenum disilicide on which a milling is performed, and sintering the resultant powder under the atmosphere of hydrogen or argon gas.

Fabrication method for molybdenum disilicide sintered body

An Ni--Cr--W base alloy having superior creep strength and excellent corrosion resistance consists essentially of: by weight 21 to 25% of Cr, 18 to 25% of W, 0.5 to 2.0% Ti, 1 to 5% of Al, between zero and 0.2% of B, 0.025 to 0.5% of C, between zero and 0.3% of Zr and 0.3 to 3.0% of Ta, the balance being substantially Ni.

Heat resistant Ni-Cr-W base alloy

An Ni--Cr--W--Al--Ti--Ta alloy exhibiting an improved high creep rupture strength and a corrosion resistance contains by weight, 12 to 20% of Cr, 18 to 25% of W, 1 to 3% of Al, 0.2 to 1.5% of Ti, 0.2 to 1.5% of Ta, 0.02 to 0.3% of C, less than 0.1% of B, less than 0.2% of Zr and the balance being substantially Ni.

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Seoul, South Korea

Ju Choi