Kennametal Inc.

Kennamental Inc

Robert D Nixon

Pankaj K Mehrotra

Joyce L Swiokla

Provided is a silicon nitride based ceramic which is particularly useful for use as a cutting tool in the high speed chip forming machining of metallic materials. The ceramic is preferably composed of at least 85 volume percent (v/o) beta silicon nitride phase and less than about 5 v/o intergranular phase. The ceramic has greater than 0.2 weight percent (w/o) magnesia, greater than 0.2 w/o yttria, where the sum of magnesia and yttria is less than 5 w/o. The ceramic preferably has less than 0.2 v/o porosity.

Silicon nitride ceramic and cutting tool made thereof

Provided is a silicon nitride based ceramic which is particularly useful for use as a cutting tool in the high speed chip forming machining of metallic materials. The ceramic is preferably composed of at least 85 volume percent (v/o) beta silicon nitride phase and less than about 5 v/o intergranular phase. The ceramic has greater than 0.2 weight percent (w/o) magnesia, greater than 0.2 w/o yttria, where the sum of magnesia and yttria is less than 5 w/o. The ceramic has less than 0.2 v/o porosity.

A ceramic material for use as a cutting tool in the high speed machining of high temperature alloys and cast irons is provided with a composition of beta prime sialon (Si.sub.6-z Al.sub.z O.sub.z N.sub.8-2 ; where 1&lt;Z&lt;3) and intergranular phase. The material has high wear resistance and reliability when used in the high speed machining of high temperature alloys at speeds of 300 to 1500 surface feet per minute.

Growing community of inventors

Greensburg, PA, United States of America

Robert D Nixon