Strength and interfactial strength of ceramic layers on metal

HI! I'm looking for information on how to assess the mechanical integrity of ceramic layers on a metal substrate. So imagine you have a ductile base metal with an oxide outer layer.
Stainless steel with chrome oxide outer surface. Now in tension or a 3 point bend test how do you assess how the oxide layer cracks and debonds. Specifically I"m interested in interfacial strength and oxide layer thickness as critical parameters to keeping the oxide stuck to a deforming substrate. I've never thought about this but any experiences, references or ideas are most appreciated.
Thanks.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The oxide layer should be very thin. I think the SEM images of intersection view can give you the thickness of oxide layer.
For the interfacial strength, it differs a lot in the different loading conditions. It badly depends on the mode mixity. I think DCB (double cantilever bending) can give your interfacial strength in mode I (openning mode), 3-point or 4 point bending or ENF (End Nothed Flexure) will give you the interfacial strength in mode II (shearing mode), which is much higher that mode I interfacial strength. MMB (mixed mode bending) can give you the interfacial strength in series of mode mixity, from DCB to large ratio of mode II over mode I.
For the setup and calculation, you can google DCB, MMB, ENF and so on to get the equations to calculate the strength from the loading force.
Good luck,
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks a lot Bob. Excellent information. I'll look into it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Improved Interfacial Mechanical Properties Of Al2O3-13wt%TiO2Coatings Derived From Nanocrystalline Powders": P. Bansal, N.P. Padture And A. Vasiliev, Acta Materialia 51(2003), pp:2959/ 70
In this - Interfacial toughness of the coatings was used as a measure of the coating strength and was quantified using the Rockwell indentation method. Research established the improved performance for coatings sprayed with nano-sized powder over those sprayed using the conventional powder. (substrate is steel)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.