X-ray mapping of interfacial regions for graphite brazed ferrous
composites
P.G. Huggett1, R. Wuhrer2
1Materials Solutions Pty Ltd, Canning Vale, 6155, Australia;
2Advanced Materials Characterisation Facility, University of Western Sydney,
Rydalmere, 2116, Australia
e: paul@materialssolutions.com.au
Abstract
A new method has been developed for brazing white cast irons and other ferrous
alloys to steel or ferrous substrates without the need to pre-machine the surfaces to
be brazed. Standard alloy brazing processes typically require adjoining surfaces to
be machined within tight tolerances, to enable capillary flow of the brazing alloy. The
new brazing process uses graphite as the brazing medium, and can be used
effectively on as-cast surfaces and “black” steel bar sections to result in an excellent
metallurgical bond between the two components being joined.
X-ray mapping has been used to study the graphite joining process. The x-ray
mapping allows the diffusion of elements within the interface regions to be studied.
Particular interest from the x-ray mapping was the detection of any non-metallic
inclusions that may be present at the interface as a result of using “as-cast” surfaces
in the joints.
The results of the x-ray mapping show the graphite based brazing produces a defect
free interface region with negligible non-metallic inclusions present, and substantial
diffusion of alloying elements such as chromium across the interface.