The present disclosure relates to the formation of polycrystalline diamond materials with fine diamond grains and nano-sized particles of a grain growth inhibitor. In one embodiment, a method of fabricating a polycrystalline diamond material is provided. The method includes providing a mixture of diamond particles with an average particle size of about 1 micron or less, distributing a plurality of nano-sized titanium-containing particles with the diamond mixture, to act as a grain growth inhibitor, and sintering the mixture of diamond particles and titanium-containing particles at high pressure and high temperature to create a polycrystalline structure of sintered diamond grains. The sintered diamond grains have an average size of about 1 micron or less.