Development and dispensing of a nickel nanoparticle ink for the diffusion brazing of a microchannel array

Research Paper


A process was developed for producing nickel nanoparticle (NiNP) films for use in diffusion-brazing stainless steel 316L microchannel laminae at 800 °C and 1 MPa of bonding pressure. NiNPs were synthesized in 45 s at 80 °C using a NiCl2·6H2O salt solution, a combination of NaBH4 and N2H5OH as reducing agents and PVP-40K as a stabilizing agent. A minimum molar ratio of 8:1 [NaOH]:[NaBH4] was required to obtain pure fcc-Ni with an average particle size of 4.2 ± 0.6 nm. Using TGA and DSC, phase change behavior was observed at temperatures as low as 720 °C. A continuous and uniform NiNP film with a thickness of 18.1 ± 2.3 μm and a roughness of 3.1 ± 0.5 μm was dispensed using a fluid pressure of 0.6 psi, a dispense gap of 1.5 mm, and a head speed of 0.5 mm/s. A microchannel array was bonded and hermetically tested up to a pressure of 120 psi with no leakage. The ultimate lap shear strength of the joint was found to be 341 ± 29 MPa. Migration of Ni into the stainless steel 316L laminae was confirmed using SEM and EDS.

Graphical Abstract


Nickel nanoparticle synthesis Ink dispensing Stainless steel Diffusion brazing Microchannel array 



The authors would like to acknowledge the financial support of the US Army (W15P7T08CV201) and the National Science Foundation under grant CBET-0654434. The authors would also like to acknowledge the financial support of the Murdock Charitable Trust (2010004) which was used to procure necessary equipment within the Microproducts Breakthrough Institute.


  1. Abu-Much R, Gedanken A (2008) Sonochemical synthesis under a magnetic field: fabrication of nickel and cobalt particles and variation of their physical properties. Chemistry 14(32):10115–10122. doi: 10.1002/chem.200801469 CrossRefGoogle Scholar
  2. Attarian Shandiz M, Safaei A, Sanjabi S, Barber ZH (2007) Modeling size dependence of melting temperature of metallic nanoparticles. J Phys Chem Solids 68(7):1396–1399. doi: 10.1016/j.jpcs.2007.02.049 CrossRefGoogle Scholar
  3. Bai L, Yuan F, Tang Q (2008) Synthesis of nickel nanoparticles with uniform size via a modified hydrazine reduction route. Mater Lett 62(15):2267–2270. doi: 10.1016/j.matlet.2007.11.061 CrossRefGoogle Scholar
  4. Castro T, Reifenberger R, Choi E, Andres RP (1990) Size-dependent melting temperature of individual nanometer-sized metallic clusters. Phys Rev B 42(13):8548CrossRefGoogle Scholar
  5. Eluri RT, Paul BK (2009) Diffusion brazing of aluminum alloys for micro heat exchanger applications. Trans N Am Manuf Res Inst SME 37:365–370Google Scholar
  6. Eluri R, Paul B (2012a) Hermetic joining of 316L stainless steel using a patterned nickel nanoparticle interlayer. J manuf Process 14(4):471–477. doi: 10.1016/j.jmapro.2012.09.007 CrossRefGoogle Scholar
  7. Eluri R, Paul B (2012b) Microwave assisted greener synthesis of nickel nanoparticles using sodium hypophosphite. Mater Lett 76:36–39. doi: 10.1016/j.matlet.2012.02.049 CrossRefGoogle Scholar
  8. Eluri R, Paul B (2012c) Synthesis of nickel nanoparticles by hydrazine reduction: mechanistic study and continuous flow synthesis. J Nanopart Res 14(4):1–14. doi: 10.1007/s11051-012-0800-1 CrossRefGoogle Scholar
  9. Hyung Dae J, Anna G, Tseng T, Brian KP, Chih-Hung C (2010) High-rate synthesis of phosphine-stabilized undecagold nanoclusters using a multilayered micromixer. Nanotechnology 21(44):445604CrossRefGoogle Scholar
  10. Jiang Q (2003) Size-dependent melting point of noble metals. Mater Chem Phys 82(1):225–227. doi: 10.1016/s0254-0584(03)00201-3 CrossRefGoogle Scholar
  11. Lu HM, Li PY, Cao ZH, Meng XK (2009) Size-, shape-, and dimensionality-dependent melting temperatures of nanocrystals. J Phys Chem C 113(18):7598–7602. doi: 10.1021/jp900314q CrossRefGoogle Scholar
  12. Luo X, Chen Y, Yue G-H, Peng D-L, Luo X (2009) Preparation of hexagonal close-packed nickel nanoparticles via a thermal decomposition approach using nickel acetate tetrahydrate as a precursor. J Alloy Compd 476(1–2):864–868. doi: 10.1016/j.jallcom.2008.09.117 CrossRefGoogle Scholar
  13. Morris JH, Gysling HJ, Reed D (1985) Electrochemistry of boron compounds. Chem Rev 85(1):51–76. doi: 10.1021/cr00065a003 CrossRefGoogle Scholar
  14. Nanda K (2009) Size-dependent melting of nanoparticles: hundred years of thermodynamic model. Pramana 72(4):617–628CrossRefGoogle Scholar
  15. Paul B (2006) Micro energy and chemical systems (MECS) and multiscale fabrication. Micromanufacturing and nanotechnology. Springer Berlin, Heidelberg, pp 299–355. doi: 10.1007/3-540-29339-6_14 CrossRefGoogle Scholar
  16. Paul BK, Lingam GK (2012) Cooling rate limitations in the diffusion bonding of microchannel arrays. J Manuf Process 14(2):119–125. doi: 10.1016/j.jmapro.2011.11.002 CrossRefGoogle Scholar
  17. Paul BK, Peterson RB (1999) Microlamination for microtechnology-based energy, chemical, and biological systems. ASME International Mechanical Engineering Congress and Exposition, Nashville, Tennessee, AES, vol 39, pp 45–52, 15–20 November 1999Google Scholar
  18. Paul BK, Kwon P, Subramanian R (2006) Understanding limits on fin aspect ratios in counterflow microchannel arrays produced by diffusion bonding. J Manuf Sci Eng 128(4):977–983. doi: 10.1115/1.2280672 CrossRefGoogle Scholar
  19. Paul B, Bose S, Palo D (2010) An internal convective heating technique for diffusion bonding arrayed microchannel architectures. Precis Eng 34(3):554–562CrossRefGoogle Scholar
  20. Paulraj P, Paul BK (2011) Metal microchannel lamination using surface mount adhesives for low-temperature heat exchangers. J Manuf Process 13(2):85–95. doi: 10.1016/j.jmapro.2011.01.001 CrossRefGoogle Scholar
  21. Qi WH, Wang MP (2004) Size and shape dependent melting temperature of metallic nanoparticles. Mater Chem Phys 88(2–3):280–284. doi: 10.1016/J.Matchemphys.2004.04.026 CrossRefGoogle Scholar
  22. Ravi Eluri BKP (2012) Synthesis of nickel nanoparticles by hydrazine reduction: mechanistic study and continuous flow synthesis. J Nanopart Res 14(4):1–4Google Scholar
  23. Slistan-Grijalva A, Herrera-Urbina R, Rivas-Silva JF, Ávalos-Borja M, Castillón-Barraza FF, Posada-Amarillas A (2008) Synthesis of silver nanoparticles in a polyvinylpyrrolidone (PVP) paste, and their optical properties in a film and in ethylene glycol. Mater Res Bull 43(1):90–96. doi: 10.1016/j.materresbull.2007.02.013 CrossRefGoogle Scholar
  24. Sridhar K, Hiroaki K, Dongsheng L, Amar SB (2004) Microwave–polyol process for metal nanophases. J Phys Condens Matter 16(14):S1305CrossRefGoogle Scholar
  25. Tiwari SK, Paul BK (2008) Application of nickel nanoparticles in diffusion bonding of stainless steel surfaces. ASME Conf Proc 48524:441–446. doi: 10.1115/msec_icmp2008-72151 Google Scholar
  26. Tiwari SK, Paul BK (2010) Comparison of nickel nanoparticle-assisted diffusion brazing of stainless steel to conventional diffusion brazing and bonding processes. J Manuf Sci Eng 132(3):030902–030905. doi: 10.1115/1.4001554 CrossRefGoogle Scholar
  27. Wu S (2003) Synthesis and characterization of nickel nanoparticles by hydrazine reduction in ethylene glycol. J Colloid Interf Sci 259(2):282–286. doi: 10.1016/s0021-9797(02)00135-2 CrossRefGoogle Scholar
  28. Zhang D, Ni X, Zheng H, Li Y, Zhang X, Yang Z (2005) Synthesis of needle-like nickel nanoparticles in water-in-oil microemulsion. Mater Lett 59(16):2011–2014. doi: 10.1016/j.matlet.2005.02.040 CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  1. 1.Mechanical, Industrial and Manufacturing EngineeringOregon State UniversityCorvallisUSA

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