Lattice and elastic constants of titanium-niobium monoborides containing   aluminum and vanadium
  First-principles electronic-structure computes the lattice and elastic constants of single-crystal TiB and NbB and changes with Nb, Ti, Al, and V solutes. The data is built into an interpolation formula for lattice and elastic constants of the quartenary (TiNbAlV)B with dilute Al and V concentrations. The lattice and elastic constants of borides in two Ti alloys containing Nb and Al are predicted from microprobe measurements. 
D. R. Trinkle