A method for producing a biodegradable magnesium metal composite that includes a polycrystalline magnesium matrix and TiB2 grains which are homogenously distributed in the polycrystalline magnesium matrix involving spark plasma sintering a milled mixture of magnesium powder and TiB2 powder. The temperature, pressure, and time of the spark plasma sintering used in the method are used to give high microharness, macrohardness, and density with low porosity by limiting the grain growth in the composite. The method yields a biodegradable magnesium metal composite having an improved microhardness, macrohardness, density, and porosity compared to other composites and methods of making composites.