ASM Online Member Community

 View Only

Centrifugal vacuum casting of metal alloys

  • 1.  Centrifugal vacuum casting of metal alloys

    Posted 01-24-2023 06:42
    Hi! I am George Xanthopoulos! The paradox of centrifugal vacuum casting to promote uniform density distribution of all constituents of metal alloys, and produce a density competing with that of wrought materials. The apparatus used for centrifugal vacuum casting of metal alloys comprises a vacuum chamber shell containing a radial arrangement of moulds pivoting on a centrifuge spindal driven by a high torque electric motor and reaching speeds of the order of magnitude of 8000 revolutions per minute or angular velocities of 48000 degrees per second, and an electric arc furnace for melting the metal alloys in a crucible made of a refractory material. The air contents within the vacuum chamber shell is withdrawn with the use of a very powerful vacuum pump so as to produce a maximum absolute pressure of 50 Pascals or 1/2027 of atmospheric pressure. Once the air of the vacuum chamber shell has been pumped out, the electric arc furnace melts the metal alloy that is in the refractory crucibles by the heat influx of infrared radiation transfer into the contents of the crucibles. Robotic equipment pours the contents of the crucibles into the moulds, and then the centrifuge is started whilst in a vacuum environment to an angular velocity of 48000 degrees per second. The molten metal alloy within the moulds slowly congeal with dissipation of heat by radiation-type heat transfer to the interior walls of the vacuum chamber shell. I speculate that due to the upper extremes of centrifugal forces of the revolving moulds that there will be different zones of composition of casting; for instance, an ascending order of increasing densities of the constituents of the metal alloy. 
    Education courses