Joined: 16 Mar 2004
|Posted: Tue Dec 05, 2006 1:52 pm Post subject: Superb nanocrystalline alloys for plating developed
|Superb nanocrystalline alloys for plating developed
With high rigidity and antiwear performance, nanocrystalline metals and their alloys can find wide applications in surface protection. However, the existence of grain boundaries often leads to erosive micro-batteries which accelerate the process of corrosion. Therefore, it has already become a key issue for surface engineering researchers to find nano materials with higher lubricating, anticorrosion and antiwear capacities.
Functionally graded nanocrystalline (NC) Ni-Co/CoO plating with excellent lubricating, anticorrosion and antiwear performances has recently been fabricated by the State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics (LICP) under CAS (Chinese Academy of Sciences).
The research group, headed by CAS member XUE Qunji and "Bairen (Hundreds Talent) Program" awardee ZHANG Junyan, originally borrowed an idea of functionally graded materials (FGMs) into the design and experiment of lubricative plating. They well controlled the deposit composition as well as the grain size and phase structure during the process of electro-deposition, and after cyclic thermal oxidation functionally graded nanocrystalline Ni-Co/CoO was successfully turned out.
In addition to enhanced corrosion resistance in both NaOH and NaCl solutions, the NC Ni-Co/CoO plating shows improved good wear resistance when compared with the NC Ni and Ni-Co graded plating under dry sliding wear conditions.
This study was reviewed as early as in April, 2005 by the Research Highlights column of Advanced Coatings and Surface Technology Alert website. The latest research result, published in Nanotechnology (vol.17, 2006), has won high praises from the magazine reviewers --"it does make a valuable contribution in the field of tribology and corrosion protection."
Source : http://www.nanowerk.com/