Moisture control in vibratory mass finishing systems

A method for precisely finishing pyrolytic carbon-coated parts, which method comprises

• providing a vibratory chamber which contains particulate media,
• supplying a predetermined amount of a liquid slurry containing micron-size polishing agent to said vibratory chamber,
• supplying pyrocarbon objects to be finished to said chamber,
• vibrating said chamber so as to cause the surfaces of said pyrocarbon-coated objects to be contacted by said media and polishing agent,
• supplying fresh liquid slurry to said chamber,
• removing liquid slurry and pyrocarbon fines in the form of a discharge slurry from a lower location in said chamber, and
• controlling the amount of said fresh slurry supplied to said chamber and the amount of discharge slurry removed from said chamber over a substantial period of time so that the amount of liquid slurry within said vibratory chamber is maintained at said predetermined amount over said substantial period of time during which precise finishing of a batch of pyrocarbon-coated objects is achieved.

Apparatus for precisely finishing pyrolytic carbon-coated parts, which apparatus comprises

• a vibratory chamber for holding a quantity of particulate media and pyrocarbon objects to be finished,
• a reservoir of fresh liquid slurry containing micron-size polishing agent,
• means for supplying a predetermined amount of liquid slurry to said vibratory chamber from said reservoir,
• means for vibrating said chamber so as to cause the surfaces of said pyrocarbon-coated objects to be contacted by said media and polishing agent,
• means for supplying fresh liquid slurry from said reservoir to said chamber,
• means for removing liquid slurry and pyrocarbon fines in the form of a discharge slurry from a lower location in said chamber,
• means for collecting said discharge slurry in a sump,
• means for monitoring the total weight of said reservoir of fresh slurry and said sump of discharge slurry, and
• control means for, upon detecting a decrease in said monitored total weight, either slowing the rate of supply of fresh slurry to said vibratory chamber or increasing the rate at which discharge slurry is removed therefrom, and for, upon detecting an increase in said monitored total weight, either increasing the rate of supply of fresh slurry to said vibratory chamber or decreasing the rate at which discharge slurry is removed therefrom,
• whereby the amount of liquid slurry within said vibratory chamber is maintained at said predetermined amount over a substantial period of time during which precise finishing of a batch of pyrocarbon-coated objects is achieved.