Re: [sdpd] Residual stress measurement by X-ray diffraction

[Jon Wright <wright...@esrf.fr>]

Chuck Blatchley wrote:

>박현민 wrote:
>
>  
>
>>I am going to get the depth profile of residual stress in ceramic material by nondestructive method such as X-ray diffraction.
>>
>>However I have no idea how to solve the problem. If let me inform an idea, I would be grateful for them.
>>
>>    
>>
>You use double scattering spectrometry. The first scattering acts as a 
>monochromator. Then, plot the "rocking" curve about the Bragg peak. 
>Stress, residual or otherwise, will broaden this peak or cause it to 
>sprout partners.
>
>Chuck B.
>  
>

Depends on the spatial resolution you want - surface versus bulk is 
easier than a full depth profile. Do you want micron or millimetre 
resolution? Do you want the stress parallel or perpendicular to the 
surface, or the full tensor? There are a variety of techniques 
available. In the home lab you can use the absorbtion of the x-rays to 
be surface sensitive and use different x-ray energies to probe different 
depths. Otherwise you can use slits to define a particular diffracting 
volume in the sample, and perhaps parallel beam geometry at a 
synchrotron. Provided you have access to a suitable instrument, a peak 
position gives you the d-spacing of the material, and therefore the 
strain (delta_d/d), which may or may not tell you what the residual 
stress is, depending on the material. Usually seems to work for stresses 
which result in >100 microstrain. You might want to validate your work 
with a destructive test....

Hope this helps,

Jon


 

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