Arc melted Ti-alloy consists high content of Mo and Fe alloying elements, was subjected to solution treatment at 900 c, followed by ice water quenched then followed by an aging treatment for 3 hrs at 400 C and finally followed by quenching.
I obtained Vicker hardness about 450 HV, so I attributed this high hardness as a result of the presence of both athermal and isothermal w phase, but unfortunately, under TEM observation only alpha or beta phase and no w.
Many litrature publications for many different composition systems confirmed on the presence of w phase after aging at around 400 C, what I can not find in my sample!
So, any help for my attribution, and how can I interpret the absence of w and in the same time the obtained high hardness.
Thanks in advance
athermal and isothermal w phase appear in some compositional range of the Ti-phase diagram. At very high beta phase stability alloys, they may not appear.
In your alloy, there may be some segregation of the beta stabilizers, which may lead to very high concentration of beta stabilizers in the sample zone under investigation. I recommend to investigate at many zones of the TEM sample.
In addition, alpha phase precipitation may be enough to raise the hardness to this level if it is so fine and so on.
athermal and isothermal w phase appear in some compositional range of the Ti-phase diagram. At very high beta phase stability alloys, they may not appear.
In your alloy, there may be some segregation of the beta stabilizers, which may lead to very high concentration of beta stabilizers in the sample zone under investigation. I recommend to investigate at many zones of the TEM sample.
In addition, alpha phase precipitation may be enough to raise the hardness to this level if it is so fine and so on.
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