Processing of amorphous Fe–W reinforced Fe matrix composites

Metal matrix composites in which crystalline Fe was reinforced by 2-phase particulates composed of an amorphous Fe alloy and nanocrystalline W were produced using a two-step mechanical alloying (MA) process. The particulates, which had a composition of Fe-40 at.% W, were prepared first by MA in a SPEX™ mill. The composite powders were then formed by blending crystalline Fe with a range (2.6–33.7) of volume percentages of the reinforcing particulates using MA, employing both SPEX™ and attritor mills. Bulk samples were produced via cold pressing and annealing and analyzed for reinforcement distribution, porosity content, and hardness. The MA blending technique was effective at producing a uniform distribution of reinforcement particles. An increase in sample hardness was seen as volume fraction reinforcement increased. Unfortunately, the effectiveness of the compaction technique decreased with increasing volume fraction reinforcement, for porosity was found to increase monotonically with the volume fraction of the reinforcement.