Ceramic Particle Reinforcements (con’t)

• Selection influences aluminum MMC processing, properties,and cost e.g.

  • Finer particles better for strength, fatigue resistance, machinability but more expensive
  • Coarser particles are easier to incorporate by stir casting but MMC is harder to machine
  • Density and size affect settling behavior in the melt
  • SiC used with cast Al-Si alloys to inhibit reactivity

• Trade-offs must be considered in the final part cost, not just at the raw material stage