PPT Slide
- GrA-Ni® - Graphitic Aluminum
- Greater Stability of Particle Distribution During Casting
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- Increased Wear Resistance
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- Improved Machinability
Notes:
- This is a relatively new member of the MMC family
- Nickel Coated Graphite particles are in the mix with SiC or Al2O3.
- The nickel coated graphite particles, mixed with the other ceramics, help in the dispersion through the matrix by a phenomenon called hindered rising.
- Basically it is a zero buoyancy activity. The ceramic groups with the graphite and forms a neutrally buoyant cluster.
- This provides two big pluses, in addition to the expected advantages of MMC’s,
- 1) better particle dispersion, even in thick section casts, and the particles stay in suspension during slow cools.
- 2) The graphite aids in machinability. The lubricating effect of the graphite helps. In addition, this also allows dry machining, benefiting environmental concerns and providing a less contaminated chip for recycling.
- As with other MMC’s, this is an engineered material and that should be taken advantage of, both in the specs of the constituents and in the advantages in the final product.