Postech Academy-industry Foundation

The Industry & Academic Cooperation in Chungnam National University

Byeong-joo Lee

Sung-hak Lee

Hyoung-seop Kim

Won-mi Choi

Sang-min Lee

Geun-Bae Lim

Hyun-Chul Park

Kun-Hong Lee

Joon-Won Kim

Woon-Bong Hwang

Dong-Seob Kim

Young-sang Na

Sun-ig Hong

Chang-woo Jeon

Seung-mun Jung

Dong-geun Kim

Seok-su Sohn

Yong-hee Jo

Present invention is about a transformation-induced plasticity high-entropy alloy which can provide improved mechanical properties compared to those obtained by conventional methods, due to the phase transformation occurring at the time of deformation at a cryogenic temperature. According to the present invention, the high-entropy alloy (HEA) includes 10-35 at % of Co, 3-15 at % of Cr, 3-15 at % of V, 35-48 at % of Fe, and 0-25 at % of Ni (exclusive of 25), and mainly consists of an FCC phase at room temperature, wherein transformation-induced plasticity, in which at least part of the FCC phase changes to a BCC phase, occurs at a cryogenic temperature (&#x2212;196&#xb0; C.)

Transformation-induced plasticity high-entropy alloy and preparation method thereof

The present invention relates to a high-entropy alloy especially having excellent low-temperature tensile strength and elongation by means of having configured, through thermodynamic calculations, an alloy composition region having an FCC single-phase microstructure at 700&#xb0; C. or higher, and enabling the FCC single-phase microstructure at room temperature and at an ultra-low temperature. The high-entropy alloy, according to the present invention, comprises: Co: 3-12 at %; Cr: 3-18 at %; Fe: 3-50 at %; Mn: 3-20 at %; Ni: 17-45 at %; V: 3-12 at %; and unavoidable impurities, wherein the ratio of the V content to the Ni content (V/Ni) is 0.5 or less, and the sum of the V content and the Co content is 22 at % or less.

High-entropy alloy for ultra-low temperature

The present invention relates to a high-entropy alloy especially having excellent low-temperature tensile strength and elongation by means of having configured, through thermodynamic calculations, an alloy composition region having an FCC single-phase microstructure at 700&#xb0; C. or higher, and enabling the FCC single-phase microstructure at room temperature and at an ultra-low temperature. The high-entropy alloy, according to the present invention, comprises: Cr: 3-18 at %; Fe: 3-60 at %; Mn: 3-40 at% ; Ni: 20-80 at %: 3-12 at %; and unavoidable impurities, wherein the ratio of the V content to the Ni content (V/Ni) is 0.5 or less.

Cr&#x2014;Fe&#x2014;Mn&#x2014;Ni&#x2014;V-based high-entropy alloy

A method for fabricating a 3D (three-dimensional) structure is disclosed to provide hydrophobicity to a surface of a 3D structure by using a dipping method in which a predetermined-shaped structure is immersed in a molten metal solution. The method includes: immersing a predetermined-shaped structure in a molten metal solution to coat a molten metal material on the surface of the predetermined-shaped structure; anodizing a metal base coated with the molten metal material; coating a polymer material on an outer surface of the metal-coated base to form a negative replica structure; covering an outer surface of the negative replica structure with an outer formation material; and removing the metal-coated base from the negative replica structure and the outer formation material.

Method for fabricating 3D structure having hydrophobic surface by dipping method

A method for fabricating a 3D (three-dimensional) structure such that the 3D structure has a surface with hydrophobicity by using a metal foil such as an aluminum foil is disclosed. The method includes preparing a metal foil base by attaching a metal foil on an outer surface of a predetermined-shaped 3D structure; anodizing the metal foil base; coating a polymer material on the outer surface of the metal foil base material to form a negative replica structure; forming an outer structure by covering an outer surface of the negative replica structure with an outer formation material; and removing the metal foil base.

Method for fabricating 3D structure having hydrophobic surface using metal foil

Growing community of inventors

Pohang-si, South Korea

Byeong-joo Lee