Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/192979

Title

Design and manufacture of Nd-Fe-B thick coatings by the thermal spray process

Author(s)

Gan, Jo Ann;  Berndt, Christopher C.

Abstract

Permanent magnetic coatings show potential in micro scale applications such as micro motors and micro generators. Nd-Fe-B magnetic coatings of average thickness 50 μm were produced via the flame spray method where the behavior of Nd-Fe-B particles in the thermal spray process was studied through single splat formation. There are generally five types of Nd-Fe-B splat morphology; which correspond to different solidification routes and varying degree of splashing. Microstructures of coating cross sections exhibit features such as cracks and porosity. The microstructural features were related to the physical properties and the brittle nature of the rare-earth alloy feedstock. Cross sections of the coatings also exhibited the presence of two distinct phases: Nd-rich and Fe-rich regions, which have been validated by EDS analysis. Metastable phase formation and decomposition followed by non-equilibrium solidification of the molten droplet prior to impact have been suggested to cause phase separation and were also identified in the formation of single splats. Hardness tests further confirmed the two distinct phases as Nd-rich and Fe-rich areas.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Engineering and Industrial Sciences. Industrial Research Institute Swinburne

Source

Surface and Coatings Technology, Vol. 205, no. 19 (Jun 2011), pp. 4697-4704

Publication year

2011

FOR Code(s)

0306 Physical Chemistry (Incl. Structural);  0912 Materials Engineering

Keyword(s)

Magnetic coating;  Microstructure;  Permanent magnet;  Rare-earth;  Thermal spray

Publisher

Elsevier

ISSN

0257-8972

Publisher URL

http://dx.doi.org/10.1016/j.surfcoat.2011.04.034

Copyright

Copyright © 2011 Elsevier B.V. All rights reserved.

Peer reviewed