Dear John,

I recommend to read this article.

Good luck

Article Synthesis of Titanium Diboride TiB2 and Ti–Al–B Metal Matrix...

This one also.

Conference Paper In-Situ Synthesis and Characterization of TiB2 and Ti-Al-B Composites

I am puzzled... You have the phase identified by XRD data which tells you it is TiB2. If this is correct you already have the Ti:B ratio, it is 1:2. Since I cannot believe that this is your real question, can you try to describe what you are really interested in?

Thanks Dear Randi Azmi for the useful related links.

Dear Gert Nolze, I purchased  a commercial TiB2 sample and want to check whether the ratio is 1:2. Now I have the XRD spectrum and I assigned the lattice planes to different peaks referring some published articles. 

Okay, No problem.

Good luck.