On the relation between microstructure and elastic constants of tungsten/steel composites fabricated by spark plasma sintering

•Tungsten/P91 steel composites were spark plasma sintered from powder mixtures.•A Fe7W6-like phase was formed between the steel and tungsten grains.•Young's and shear moduli were measured by resonant ultrasound spectroscopy.•FEM was utilized to calculate the effective elastic properties of the individual phases.•Tungsten regions showed low stiffness due to weak bonding of the tungsten grains.