It is well known that, inter alia, work hardening rate of metalic materials is stacking fault energy (SFE) dependent. Consequently, the SFE has a significant impact on properties of metalic alloys . I'm looking for the most accurate technique to estimate the SFE in materials, where significant chemical segregation is observed, e.g. alloys in the as-cast state.
Thank you Mr. Lu for your answer. I understand that EPMA or 3DAP techniques might be used to describe chemical segregation, but what with SFE?
Thank you Prof. Raabe for the very detailed information. I am also interested in this question since I am studying the SFE of copper. I will also carefully read these papers .
I recently also read some paper using neutron diffraction to calculate the SFE, the SFE will induce the shift of for example 200 and 400 peak in different direction in the neutron diffraction pattern during tensile tests. Then the SFE can be calculated following the method given in chapter 13 diffraction by imperfect crystals in book X-ray diffraction written by B E Warren. Neutron can ONLY give the average data in bulk sample. For detail information the methods suggested by Prof. Raabe is more powerful.
Thank you Prof. Raabe and Mr. Xie for very insightful and helpful answers. I would like to thank you for your time and I appreciate your knowledge in this tricky subject. Your comprehensive answers will have important guiding significance to my futher investigations. Indeed, the methods suggested by Prof. Raabe seem to be more precise. Nevertheless, I think that the proper preparation of the specimens for the proposed, very sophisticated methods, as well as performing experiments to obtain satisfactory results will be great challenge. Before I asked this question on the researchgate, I considered using neutron diffraction. However, I afraid that it might be difficult to isolate the effects of segregation and presence of stacking faults on the broaden and position of the diffraction peaks. My next question: Is it possible to isolate the effects of segregation and presence of stacking faults on the width and position of the diffraction peaks? Another idea that came to me recently is to determine the segregation in the investigated alloy, and then synthesis several alloys, which correspond chemically to different regions of the alloy. The next step would be to determine the SFE on the homogenised model alloys. Dear colleagues, what do you think about it?
Dear Krzysztof Wieczerzak,
I think you can try thermodynamic modeling of Stacking Fault Energy(SFE). In this, the underlying assumption is that SFE is a thin layer of hcp in fcc matrix. It is based on a set of equation that incorporates free energy contribution from bulk, interstitial, magnetic and segregation. Again, the segregation free energy change is dependent on chemical, surface and elastic.
In your case the alloy is significant in chemical segregation, I hope you can input the chemical composition of the alloy and determine the SFE therotically.
I have attached a ref, that might help you.
regards
Santosh
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