SILICON-NITRIDE BASED CERAMICS
Developed in the 1970s, silicon-nitride (SiN) based ceramic tool materials consist of silicon nitride with various additions of aluminium oxide, yttrium oxide and titanium carbide. These tools have toughness, hot hardness, and good thermal-shock resistance.
An example of a SiN-base material is sialon, named after the elements of which it is composed: silicon, aluminium, oxygen, and nitrogen. It has higher thermal-shock resistance than silicon nitride, and is recommended for machining cast irons and nickel-based super-alloys at intermediate cutting speeds. Because of chemical affinity to iron, SiN-based tools are not suitable for machining steels.
