Normally elastic properties display no correlation with strength (in terms of yield or ultimate stress). As to hardness, use better conventional (macro) hardness that has an

often verified correlation to the ultimate stress (not yield point). Nano is not good idea as Ti structure may be too inhomogeneous.

Hi, we have extracted yield strength of Cu6Sn5 (HCP) using nanoindentation and reverse analysis called Dao's model. You can try using it. Here is my paper which has the citation of Dao's paper and a brief description of the model.

http://link.springer.com/article/10.1007/s11664-014-2977-9

thanks for reference, I'll look at. Apparently nanoind  feels yield point since the

low deformation is closer to the beginning of diagram. At the same time, for the same reason, the method is more sensitive to any inhomogeneity; thus it will work only on pretty uniform materials.

I think that you could find useful information in the work of Guillaume Kermouche. I suggest the following papers to you (if you have difficulties getting them feel free to ask me) :

G. Kermouche, J.L. Loubet, J.M. Bergheau, « An approximate solution to the problem of cone or wedge indentation of elastoplastic solids», Comptes rendus mécanique, Vol. 333, Issue 5, May 2005, pp.389-395.

G. Kermouche, J.L. Loubet, J.M. Bergheau, “ A new index to estimate the strain rate sensitivity of glassy polymers using conical/pyramidal indentation”, Philosophical Magazine, Vol. 86, Issue 33, Dec. 2006, pp.5667-5677.

G. Kermouche, J.L. Loubet, J.M. Bergheau, “ Cone indentation of time-dependent materials: The effects of the indentation strain rate”, Mechanics of Materials, Vol. 39, Issue 1, Jan. 2007, pp. 24-38.

Yield Strength can be obtained by nanoindentation if a spherical tip is used. The advantage of using a spherical tip over sharp tips such as Berkovich or Vikers  is that the deformation starts elastically and with an increase in applied load, deformation will become plastic, whereas, if Berkovich tip is used, due to high local stresses under the tip, plastic deformation is introduced from the very beginning of indentation. In a nut shell, I recommend using a spherical tip and and extract the yield stress in much the same way it is extracted from tensile stress-strain curves. The relations for stress and strain as function of indentation depth can be found in the paper whose link is provided below. 

http://link.springer.com/article/10.1007%2Fs00339-002-1669-0#page-1

Yield strength can be obtained from nanoindentation testing even with sharp indenters such as Berkovich and Vickers. In the case of a Berkovich indenter, perform the indentation at a specific load and vary the loading rates. If your material is strain-rate sensitive, the hardness will increase with the loading rate. Then using Tabor's relation, H= 3Y, where Y is the yield strength to establish the Y at each loading rate. Use strain-rate model to get the intrinsic hardness and convert the intrinsic hardness to the yield strength using the Tabor's relation. I have used the above method for zirconia and the yield strength of 4.36 GPa is consistent with the yield strength of the same material using another nanoindentation method by another authors. I attach both papers for your reference.

The attached reference may also be relevant to your question/research

The attached reference may also be relevant to your question/research

Please find attached file. It might be helpful.