Method of using Si.sub.3 N.sub.4.Y.sub.2 O.sub.3.SiO.sub.2 ceramic system for machining cast iron
AssigneeFord Motor Company
InventorsShyam K. Samanta, Krishnamoorthy Subramanian, Andre Ezis
Life of this patent
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Abstract
A process for continuous or interrupted machine cutting of solid cast iron by milling, turning or boring with a shaped tool, wherein said shaped tool is a ceramic consisting essentially of Si.sub.3 N.sub.4 and 4-12% by weight Y.sub.2 O.sub.3, produced by hot pressing at a pressure and a temperature of 1700.degree.-1750.degree. C. to achieve substantially full density.
Claims5
A process for continuous or interrupted machine cutting of solid cast iron stock by milling, turning or boring with a shaped tool wherein said shaped tool is a ceramic consisting essentially of Si.sub.3 N.sub.4 and 4-12% by weight Y.sub.2 O.sub.3, produced by hot pressing at a predetermined pressure, said pressure being maintained continuously during heating at an ultimate pressing temperature of 1700.degree.-1750.degree. C. until a density of at least 3.25 g/cm.sup.3 is obtained and shaping the hot pressed ceramic into a cutting tool.
A process for continuous or interrupted machine cutting of solid cast iron stock by milling, turning or boring with a shaped tool wherein said shaped tool consists essentially of a ceramic of Si.sub.3 N.sub.4.SiO.sub.2.Y.sub.2 O.sub.3 with milling media impurities, said SiO.sub.2 being present as an oxide surface coating on the grains of said Si.sub.3 N.sub.4 and said Y.sub.2 O.sub.3 being present in an amount of 4-12%, said ceramic having been produced by hot pressing at a predetermined pressure, temperature and time period to effect a density of at least 3.25 g/cm.sup.3.
Dependencies are inferred from the claim text.