  We use density matrix renormalization group to investigate the phase diagram
of the Fermi Hubbard model on a triangular lattice with densities above
half-filling, $1 \leq n < 2$. We discuss the important role of kinetic
magnetism and magnetic polarons. For strong interactions and low doublon
dopings, attractive interaction between polarons results in phase separation
between the fully polarized state at finite doping and the commensurate
spin-density wave state at half-filling. For intermediate interaction strength
and small doping, competition between antiferromagnetic superexchange and
kinetic magnetism gives rise to the incommensurate spin density wave (I-SDW)
phase. Fully polarized ferromagnetic (FPF) phase for weak interactions is
limited to dopings close to the van Hove singularity in the density of states.
With increasing interactions the FPF phase expands to lower dopings. For strong
interactions it reaches the low doping regime and is better understood as
arising from proliferation of Nagaoka-type ferromagnetic polarons. Other phases
that we find include a partially polarized phase, another type of I-SDW at high
densities, and M\"uller-Hartmann ferromagnetism close to the band insulating
regime.
