Cutting tool insert and method for producing the same
AssigneeSandvik Intellectual Property AB
InventorGunnar Brandt
Life of this patent
Estimating the term…
Abstract
An improved cutting tool insert and a method for the preparation of such cutting tool insert, having a sintered alumina and silicon carbide whisker composite material body, comprising the steps of milling and mixing the powdered starting materials of said composite material and forming said material into a preformed workpiece, heating up said workpiece at a heating rate of from about 20 to about 60° C. per minute to a sintering temperature of between from about 1600 to about 2300° C., and holding at said sintering temperature for a holding time of from about 5 to about 60 minutes at a pressure of between from about 20 to about 100 MPa.
Claims29
The method for the preparation of a cutting tool insert having a sintered alumina and silicon carbide whisker composite material body, comprising the steps of
- milling and mixing powders of alumina and silicon carbide whiskers;
- forming said mixture into a preformed workpiece;
- heating said workpiece at a heating rate of from about 20 to about 60° C. per minute by applying electrical energy in the form of a DC current that at least partially goes through said workpiece to a sintering temperature of between from 1800 to about 2300° C.;
- and
- holding said workpiece at said sintering temperature for a holding time of from about 5 to about 60 minutes at a pressure of between 20 to 100 MPa,
- wherein the proportion of silicon carbide whiskers in said composite material is from about 5 to about 50 % by volume and said alumina grain size in said composite material has a 80th percentile (P80) of less than 2.5 μm.
Dependencies are inferred from the claim text.