Vacuum Brazing

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform

Zobač Marti - One of the best experts on this subject based on the ideXlab platform.

Teo Kenneth - One of the best experts on this subject based on the ideXlab platform.

  • Active Vacuum Brazing of CNT films to metal substrates for superior electron field emission performance
    'IOP Publishing', 2015
    Co-Authors: Longti Rémi, Sánchez Valencia, Jua Ramó, Shorubalko Iva, Furre Roma, Hack Erwi, Elsene Hansrudolf, Gröning Olive, Greenwood Paul, Rupesinghe Nali, Teo Kenneth
    Abstract:

    The joining of macroscopic films of vertically aligned multiwalled carbon nanotubes (CNTs) to titanium substrates is demonstrated by active Vacuum Brazing at 820 °C with a Ag–Cu–Ti alloy and at 880 °C with a Cu–Sn–Ti–Zr alloy. The Brazing methodology was elaborated in order to enable the production of highly electrically and thermally conductive CNT/metal substrate contacts. The interfacial electrical resistances of the joints were measured to be as low as 0.35 Ω. The improved interfacial transport properties in the brazed films lead to superior electron fieldemission properties when compared to the as-grown films. An emission current of 150 μA was drawn from the brazed nanotubes at an applied electric field of 0.6 V μm−1. The improvement in electron field-emission is mainly attributed to the reduction of the contact resistance between the nanotubes and the substrate. The joints have high re-melting temperatures up to the solidus temperatures of the alloys; far greater than what is achievable with standard solders, thus expanding the application potential of CNT films to high-current and high-power applications where substantial frictional or resistive heating is expecte

  • Active Vacuum Brazing of CNT films to metal substrates for superior electron field emission performance
    Institute of Physics Publishing, 2015
    Co-Authors: Longti Rémi, Shorubalko Iva, Furre Roma, Hack Erwi, Elsene Hansrudolf, Gröning Olive, Greenwood Paul, Rupesinghe Nali, Teo Kenneth
    Abstract:

    The joining of macroscopic films of vertically aligned multiwalled carbon nanotubes (CNTs) to titanium substrates is demonstrated by active Vacuum Brazing at 820 °C with a Ag–Cu–Ti alloy and at 880 °C with a Cu–Sn–Ti–Zr alloy. The Brazing methodology was elaborated in order to enable the production of highly electrically and thermally conductive CNT/metal substrate contacts. The interfacial electrical resistances of the joints were measured to be as low as 0.35 Ω. The improved interfacial transport properties in the brazed films lead to superior electron fieldemission properties when compared to the as-grown films. An emission current of 150 μA was drawn from the brazed nanotubes at an applied electric field of 0.6 V μm−1. The improvement in electron field-emission is mainly attributed to the reduction of the contact resistance between the nanotubes and the substrate. The joints have high re-melting temperatures up to the solidus temperatures of the alloys; far greater than what is achievable with standard solders, thus expanding the application potential of CNT films to high-current and high-power applications where substantial frictional or resistive heating is expectedPeer reviewe

K. Muraleedharan - One of the best experts on this subject based on the ideXlab platform.

  • Structural Properties of brazed Ti joint using Ti20Zr20Cu40Ni20 metallic glass ribbon as filler
    Materials Research Express, 2018
    Co-Authors: B. Majumdar, Anil K. Bhatnagar, K. Muraleedharan
    Abstract:

    In the present investigation, we present our results on characterization of Ti joints, brazed with metallic glass ribbons of Ti20Zr20Cu40Ni20 alloy. Initially, metallic glass ribbons were produced using a Vacuum melt spinner and used as filler materials for Vacuum Brazing of two Ti alloy plates at 967 degrees C for period of 10 min. Field-Emission Scanning Electron Microscopy (FESEM), the as-spun ribbons showed fully amorphous structure when examined on both surfaces byXRDand also verified byTEM investigation. The Brazing joint of two Ti-plates using the metallic glass ribbon was found to be very sound. FESEM characterization of the cross-sectioned Brazing joint shows sub-micron size grains uniformly distributed in the matrix with brighter appearance. EDXanalysis revealed that the submicron grains are rich in Ti, while the matrix phase has Zr-enrichment. Back Scattered Electron (BSE) image also suggested substantial reaction of the Brazing ribbon with Ti plates, whose typical lath microstructure is modified to nanostructured lamellar eutectic microstructure comprising of Ti-rich and Zr-enriched phases.

Muraleedhara K - One of the best experts on this subject based on the ideXlab platform.

  • Microstructural Evolution of Brazed Ti-joint Using Ti20Zr20Cu50Ni10 Metallic Glass Ribbon as Filler
    2019
    Co-Authors: Rao P Rama, Hatnagar, Anil K, Majumda Haska, Muraleedhara K
    Abstract:

    Metallic glasses of Ti20Zr20Cu50Ni10 in the form of hard ribbon were produced by the standard melt-spinning technique on copper roller wheel in air. Vacuum Brazing using these ribbons were done to join two plates of Ti alloy at 990 K for a period of 10 min. The main aim of the present work was to study the use of the metallic glass ribbons as Brazing material for titanium based alloys. Since the microstructure during crystallization of these metallic glasses is expected to influence the strength of Brazing joints, microstructure characterization is very important. Here we present the results of characterization of the ribbons with Ti20Zr20Cu50Ni10 composition as well as the brazed sample after joining two Ti-plates. Both as-spun and heat-treated ribbon were characterized by X-ray Diffractometry (XRD), Field-Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM) and the energy dispersive X-ray spectroscopy (EDX) attached to both TEM and FESEM. The as-prepared ribbons showed amorphous nature when examined on both surfaces by XRD and as was also verified by TEM study of heat treated (753 K, 30 min.) ribbon showed formation of nanocrystalline microstructure comprised of equiaxed grains having sizes in the range of about 50-200 nm. Electron diffraction analysis in the TEM suggested the presence of two phases, viz., cubic Ti2Ni and (Ti, Zr)(2)Ni phases. (C) 2019 The Authors. Published by Elsevier B.V

Longti Rémi - One of the best experts on this subject based on the ideXlab platform.

  • Active Vacuum Brazing of CNT films to metal substrates for superior electron field emission performance
    'IOP Publishing', 2015
    Co-Authors: Longti Rémi, Sánchez Valencia, Jua Ramó, Shorubalko Iva, Furre Roma, Hack Erwi, Elsene Hansrudolf, Gröning Olive, Greenwood Paul, Rupesinghe Nali, Teo Kenneth
    Abstract:

    The joining of macroscopic films of vertically aligned multiwalled carbon nanotubes (CNTs) to titanium substrates is demonstrated by active Vacuum Brazing at 820 °C with a Ag–Cu–Ti alloy and at 880 °C with a Cu–Sn–Ti–Zr alloy. The Brazing methodology was elaborated in order to enable the production of highly electrically and thermally conductive CNT/metal substrate contacts. The interfacial electrical resistances of the joints were measured to be as low as 0.35 Ω. The improved interfacial transport properties in the brazed films lead to superior electron fieldemission properties when compared to the as-grown films. An emission current of 150 μA was drawn from the brazed nanotubes at an applied electric field of 0.6 V μm−1. The improvement in electron field-emission is mainly attributed to the reduction of the contact resistance between the nanotubes and the substrate. The joints have high re-melting temperatures up to the solidus temperatures of the alloys; far greater than what is achievable with standard solders, thus expanding the application potential of CNT films to high-current and high-power applications where substantial frictional or resistive heating is expecte

  • Active Vacuum Brazing of CNT films to metal substrates for superior electron field emission performance
    Institute of Physics Publishing, 2015
    Co-Authors: Longti Rémi, Shorubalko Iva, Furre Roma, Hack Erwi, Elsene Hansrudolf, Gröning Olive, Greenwood Paul, Rupesinghe Nali, Teo Kenneth
    Abstract:

    The joining of macroscopic films of vertically aligned multiwalled carbon nanotubes (CNTs) to titanium substrates is demonstrated by active Vacuum Brazing at 820 °C with a Ag–Cu–Ti alloy and at 880 °C with a Cu–Sn–Ti–Zr alloy. The Brazing methodology was elaborated in order to enable the production of highly electrically and thermally conductive CNT/metal substrate contacts. The interfacial electrical resistances of the joints were measured to be as low as 0.35 Ω. The improved interfacial transport properties in the brazed films lead to superior electron fieldemission properties when compared to the as-grown films. An emission current of 150 μA was drawn from the brazed nanotubes at an applied electric field of 0.6 V μm−1. The improvement in electron field-emission is mainly attributed to the reduction of the contact resistance between the nanotubes and the substrate. The joints have high re-melting temperatures up to the solidus temperatures of the alloys; far greater than what is achievable with standard solders, thus expanding the application potential of CNT films to high-current and high-power applications where substantial frictional or resistive heating is expectedPeer reviewe