کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1697147 | 1012038 | 2012 | 7 صفحه PDF | دانلود رایگان |
This paper evaluates the use of a nickel nanoparticle (NiNP) interlayer for making hermetic joints in 316L stainless steel substrates via diffusion brazing. Different NiNP inks were prepared using commercial nanopowder (∼9 nm) and in-house synthesized nanoparticles. Syringe pump deposition of ∼9 nm NiNP ink and diffusion brazing at 900 °C for 30 min under 2 MPa resulted in a hermetic joint up to the tested pressure of 70 psi. In-house synthesis of NiNPs was carried out in ethylene glycol by the reduction of NiCl2·6H2O in the presence of hydrazine (N2H4) as a reducing agent. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) results confirm the presence of pure fcc-Ni with an average particle size of 5.4 ± 0.9 nm. An as-synthesized suspension of NiNPs was patterned onto 316L stainless steel laminae via automated dispensing to a thickness of ∼3 μm and bonded at 800 °C for 30 min at a pressure of 2 MPa. The diffusion-brazed test article was also found to be hermetic up to 70 psi. An examination of the bond line using scanning electron microscopy (SEM) showed good uniformity and continuity.
► Nickel nanoparticle ink was successfully prepared from ∼9 nm dry powder.
► A deposition method using needle dispensing was demonstrated for NiNP ink.
► Stable NiNP (∼5.4 nm) ink was prepared in-house via modified polyol process.
► A ∼2 μm layer of NiNP was deposited via automated dispenser.
► In-house prepared ink resulted in lowering of brazing temperature by 100 °C.
Journal: Journal of Manufacturing Processes - Volume 14, Issue 4, October 2012, Pages 471–477