Yonsei University

Korea Institute of Science and Technology

Do Hyang Kim

Won Tae Kim

Eun Soo Park

Hye Jung Chang

Jin Kyu Lee

Dong Hyun Bae

Ju Yeon Lee

Min Ha Lee

Jae Chul Lee

Yu Chan Kim

Daniel J Sordelet

Hyun Kyu Lim

Eric Fleury

Joon Seok Kyeong

Byung Joo Park

Seong Hoon Yi

Hwi Jun Kim

Jung Chan Bae

Jong Hyun Na

Jong Shim Jang

Ju Gun Park

Men Hua

Tae Gyu Park

Eun Young Jeong

Sheng Hoon Yi

Provided is a Nd-based two-phase separation amorphous alloy by adding an element having a big difference in heat of mixing in a Nd-based alloy with a superior amorphous formability through an inherent characteristic of compositional elements and consideration of thermodynamics, at the time of forming amorphous phase, to thereby enable two-phase separation amorphous alloy during solidification. The Nd-based two-phase separation amorphous alloy is represented as a general equation Nd(TM)(D)wherein TM is a combination selected from A-B, A-C and B&#x2014;C when an element group of A consists of Y, Ti, Zr, La, Pr, Gd and Hf, an element group of B consists of Fe and Mn, and an element group of C consists of Co, Ni, Cu and Ag, wherein the content of the element group which constitutes the combination is 5 atomic weight % or greater, and the element selected from each of the element group is at least one element, and the content of one element selected from each of the element group does not exceed 50 atomic weight %, wherein the content of the element group of B is less than that of the element group of C when TM is a B&#x2014;C combination, and wherein D is at least one selected from the group consisting of Al, B, Si and P, and a and b have the range of 20&#x2266;a&#x2266;70, 5&#x2266;b&#x2266;30, and a+b&#x2267;40 in terms of atomic weight %.

Nd-based two-phase separation amorphous alloy

Disclosed is a magnesium based amorphous alloy having a good glass forming ability and ductility. The Mg based amorphous alloy has a composition range of MgABwhere x and y are respectively 2.5&#x2266;x&#x2266;30, 2.5&#x2266;y&#x2266;20 in atomic percent. Here, A includes at least one element selected from the group consisting of Cu, Ni, Zn, Al, Ag, and Pd, and B includes at least one element selected from the group consisting of Gd, Y, Ca, and Nd.

Magnesium based amorphous alloy having improved glass forming ability and ductility

In Cu-based bulk amorphous matrix composite materials, comprising a Cu-based amorphous alloy containing high fusion point element(s) selected from a group of Ta, W or combination thereof, wherein the high fusion point element(s) has(have) a shape of crystalline grain and is(are) dispersed around a Cu-based amorphous matrix. Cu-based bulk amorphous matrix composite materials have the composition expressed as the following Chemical formula 1;CuZrTiR&#x2003;&#x2003;[Chemical formula 1]

Method for producing composite materials comprising Cu-based amorphous alloy and high fusion point element and composite materials produced by the method

Disclosed is a single-phase amorphous alloy having an enhanced ductility. The single-phase amorphous alloy has a composition range of ABCwhere a and b are respectively 0&#x3c;a&#x3c;15, 0&#x2266;b&#x2266;30 in atomic percent. Here, A includes at least one element selected from the group consisting of Be, Mg, Ca, Ti, Zr, Hf, Pt, Pd, Fe, Ni, and Cu. B includes at least one element selected from the group consisting of Y, La, Gd, Nb, Ta, Ag, Au, Co, and Zn. C includes at least one element selected from the group consisting of Al, In, Sn, B, C, Si, and P.

Monolithic metallic glasses with enhanced ductility

A ductile particle-reinforced amorphous matrix composite characterized in that ductile powder is dispersed into amorphous matrix and the mixture is plastically worked to be consolidated and a method for manufacturing the same are provided. The amorphous powder includes any alloy, which can be produced in the form of amorphous structure and which is selected from the group consisting of Ni-, Ti-, Zr-, Al-, Fe-, La-, Cu- and Mg-based alloys. The method for manufacturing a ductile particle-reinforced amorphous matrix composite, the method comprising steps of preparing a mixture consisting of amorphous powder and ductile powder, obtaining a billet by compacting the mixture in a hermetically sealing condition, and plastic working the mixture by processing the billet at the temperature in the super-cooled liquid region of the amorphous alloy.

Ductile particle-reinforced amorphous matrix composite and method for manufacturing the same

Disclosed is a quasicrystalline phase-reinforced Mg-based metallic alloy with high warm and hot formability, and making method thereof. The metallic alloy comprises a composition of Mg&mdash;1&tilde;10 at % Zn&mdash;0.1&tilde;3 at % Y, in which a two-phase region consisting of a quascrystalline phase and a magnesium-based solid solution phase exists. Constituting a matrix structure, the Mg-based solid solution phase (&agr;&mdash;Mg) is formed as a primary solid phase upon solidification. The quasicrystalline phase serves as a second phase and forms, together with the Mg-based solid solution phase, a eutectic phase, thereby reinforcing the matrix. The materials obtained through the hot rolling or extrusion of the cast alloy have an increased volume % of the second phase and thus show significantly increased strength.

Quasicrystalline phase-reinforced Mg-based metallic alloy with high warm and hot formability and method of making the same

Disclosed are nickel-based amorphous alloy compositions, and particularly quaternary nickel-based amorphous alloy compositions containing nickel, zirconium and titanium as main constituent elements and additive Si or P, the quaternary nickel-zirconium-titanium-silicon alloy compositions comprising nickel in the range of 45 to 63 atomic %, zirconium plus titanium in the range of 32 to 48 atomic % and silicon in the range of 1 to 11 atomic %, and being represented by the general formula: Ni,(Zr,Ti,),Si,. Also, at least one kind of element selected from the group consisting of V, Cr, Mn, Cu, Co, W, Sn, Mo, Y, C, B, P, Al can be added to the alloy compositions in the range of content of 2 to 15 atomic %. The quaternary nickel-zirconium-titanium-phosphorus alloy compositions comprising nickel in the range of 50 to 62 atomic %, zirconium plus titanium in the range of 33 to 46 atomic % and phosphorus in the range of 3 to 8 atomic %, and being represented by the general formula: Ni,(Zr,Ti,),P,. The nickel-based amorphous alloy compositions have a superior amorphous phase-forming ability to produce the bulk amorphous alloy having a thickness of 1 mm by general casting methods.

Nickel-based amorphous alloy compositions

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Do Hyang Kim