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Journal of Materials Science

, Volume 13, Issue 2, pp 329–335 | Cite as

Production of cast aluminium-graphite particle composites using a pellet method

  • B. C. Pai
  • P. K. Rohatgi
Papers

Abstract

Copper- and nickel-coated graphite particles can be successfully introduced into aluminium-base alloy melts as pellets to produce cast aluminium-graphite particle composites. The pellets were made by pressing mixtures of nickel- or copper-coated graphite particles and aluminium powders together at pressures varying between 2 and 20 kg mm−2. These pellets were dispersed in aluminium alloy melts by plunging and holding them in the melts using a refractory coated mild steel cone, until the pellets disintegrated and the powders were dispersed. The optimum pressure for the preparation of pellets was 2 to 5 kg mm−2 and the optimum size and percentage of aluminium powder were 400 to 1000μm and 35 wt% respectively. Under optimum conditions the recovery of the graphite particles in the castings was as high as 96%, these particles being pushed into the last freezing interdendritic regions. The tensile strength and the hardness of the graphite aluminium alloys made using the pellet method are comparable to those of similar composites made using gas injection or the vortex method. The pellet method however has the advantage of greater reproducibility and flexibility. Dispersion of graphite particles in the matrix of cast aluminium alloys using the pellet method increases their resistance to wear.

Keywords

Vortex Aluminium Alloy Mild Steel Graphite Particle Aluminium Powder 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman and Hall Ltd. 1978

Authors and Affiliations

  • B. C. Pai
    • 1
  • P. K. Rohatgi
    • 2
  1. 1.Materials Science DivisionNational Aeronautical LaboratoryBangaloreIndia
  2. 2.Department of Mechanical EngineeringIndian Institute of ScienceBangaloreIndia

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