Effect of phase composition on the internal friction and magnetostriction in the L12/D03 biphase Fe-27Ga alloys

•L12 phase has a big effect on Snoek-type (P1) and Zener-type (P2) relaxation peaks.•Magneto-mechanical damping of the D03 phase is distinctly larger than L12 phase.•Non-magnetic damping of L12 phase (FCC) is obviously larger than D03 (BCC) phase.•L12 phase has a higher IF/magnetostriction under the higher stress/magnetic field.•Domain movement of L12 phase need higher stress or magnetic fields than BCC phase.