Diffusional evolution of σ-phase to resolve a long-standing dissimilar material joining issue in supercritical boiler

Nanofluidics is supposed to take advantage of a variety of new physical phenomena and unusual effects at nanoscales typically below 100 nm. However, the current chip-based nanofluidic applications are mostly based on the use of nanochannels with linewidths above 100 nm, due to the restricted ability of the efficient fabrication of nanochannels with narrow linewidths in glass substrates. In this study, we established the fabrication of nanofluidic structures in glass substrates with narrow linewidths of several tens of nanometers by optimizing a nanofabrication process composed of electron-beam lithography and plasma dry etching. Using the optimized process, we achieved the efficient fabrication of fine glass nanochannels with sub-40 nm linewidths, uniform lateral features, and smooth morphologies, in an accurate and precise way. Furthermore, the use of the process allowed the integration of similar or dissimilar material-based ultrasmall nanocomponents in the ultranarrow nanochannels, including arrays of pockets with volumes as less as 42 zeptoliters (zL, 10−21 L) and well-defined gold nanogaps as narrow as 19 nm. We believe that the established nanofabrication process will be very useful for expanding fundamental research and in further improving the applications of nanofluidic devices.

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Dissimilar material joining using laser (aluminum to steel using zinc-based filler wire)

Optics & Laser Technology ◽

10.1016/j.optlastec.2005.08.014 ◽

2007 ◽

Vol 39 (3) ◽

pp. 652-661 ◽

Cited By ~ 153

Author(s):

Alexandre Mathieu ◽

Rajashekar Shabadi ◽

Alexis Deschamps ◽

Michel Suery ◽

Simone Matteï ◽

...

Keyword(s):

Dissimilar Material ◽

Filler Wire

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Dynamic precipitation of σ-phase and element partitioning in equiatomic CoCrFeMnNi high-entropy alloy

Materials Science and Engineering A ◽

10.1016/j.msea.2021.140739 ◽

2021 ◽

pp. 140739

Author(s):

Unhae Lee ◽

Boris Straumal ◽

Nokeun Park

Keyword(s):

High Entropy Alloy ◽

Dynamic Precipitation ◽

Σ Phase ◽

High Entropy ◽

Element Partitioning

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On the compositional and structural redistribution during partial recrystallisation: a case of σ-phase precipitation in a Mo-doped NiCoCr medium-entropy alloy

Scripta Materialia ◽

10.1016/j.scriptamat.2020.113662 ◽

2021 ◽

Vol 194 ◽

pp. 113662

Author(s):

Junyang He ◽

Xiaoxiang Wu ◽

Yueling Guo ◽

Surendra Kumar Makineni

Keyword(s):

Phase Precipitation ◽

Σ Phase

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Microstructure and Properties of 304 Stainless Steel Specimen Manufactured by Cold Metal Transfer + Pulse Composite Arc Additive

Science of Advanced Materials ◽

10.1166/sam.2021.3876 ◽

2021 ◽

Vol 13 (1) ◽

pp. 152-160

Author(s):

Yanjie Wang ◽

Xuru Hou ◽

Lin Zhao ◽

Yun Peng ◽

Chengyong Ma ◽

...

Keyword(s):

Stainless Steel ◽

Additive Manufacturing ◽

Fracture Surface ◽

Steel Specimen ◽

Corrosion Current ◽

Electrochemical Analysis ◽

304 Stainless Steel ◽

Cold Metal Transfer ◽

Σ Phase ◽

Microstructure And Properties

304 stainless steel test block was fabricated by continuous melting wire with CMT and pulse mixed mode, and the path of additive manufacturing is layered slice S-shaped. The relationship between microstructure and properties of the specimen was investigated by microscope, SEM, EBSD, XRD, tensile, impact and electrochemical experiments. The results show that molding between weld and weld is very good, and the microstructure is mainly Austenite, Ferrite and a little of σ, and there are three kinds of Ferrite morphology: cellular, wormlike and lath. σ phase precipitates easily in regions with high ferrite content and is distributed at the boundary between austenite and ferrite. The specimen has good low temperature toughness. The microscopic fracture surface is mainly dimple, and the precipitates in the fracture surface are mainly fine carbide particles. The tensile strength of the additive manufacturing 304 specimen is higher than the forged specimen, and the type of fracture is ductile fracture. The electrochemical analysis of 304 stainless steel specimens and forgings shows that CMT and pulse arc additive manufacturing specimen has excellent corrosion resistance and its corrosion current is slightly lower than the forging.

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