Strong particles in Metal

We all know that strong fibers make most of today¹s composite materials what they are : exceptionally stiff, strong, light and tough materials that serve in a number of demanding structural applications. This presentation will try to make the case for strong particles, proposing that they hold equally high promise as a reinforcing phase in metal ¬ if they can be made to be as strong as today¹s engineering fibres. The talk will be articulated in two parts. In the first, experimental data from the author¹s laboratory, combined with simple micromechanical calculations, will be used to show how strong ceramic particles combined with metal do indeed have the potential to produce highly attractive materials. The second part of the presentation will address the question of measuring particle strength : unlike fibres, which are easily tested in uniaxial tension, miroscopic second phases or particles used for the reinforcement of metals are far more difficult to characterize for strength. A few methods devised to this end in recent work within the author¹s laboratory will be presented, together with experimental results gathered on strong brittle particles that are, or can be, used, for the reinforcement of metals. The presentation will conclude with a few practical implications of this work.