Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

New ceramics and cermets for rotationally symmetric tools

A new generation of hard materials (ceramics and cermets) for use in rotationally symmetric machining operations (drilling, reaming, and milling) has been developed. The methodology used to achieve this goal has consisted of:
developing new ceramics, cermets, and submicron grain cemented carbides;
characterizing these newly developed materials in terms of physical and mechanical properties, microstructure, and functional properties;
designing geometries for rotationally symmetric tools adapted to the properties of these hard materials;
developing production methods for machining the new tools;
evaluating the hard tool materials using field tests;
optimizing the new tools in terms of materials development, geometrical design, and production techniques.

New materials developed include:
new silicon nitride and cermet grades with improved hardness and toughness for the intended application;
an alumina grade hardened and toughened by titanium carbide, which can be densified in complex shape;
a submicron grade carbide.

New tools designed, fabricated and tested include:
a silicon nitride drill and a silicon nitride end mill with optimized geometry for machining cast iron;
a cermet reamer and cermet end mill for machining steel;
a cermet end mill for machining aluminium silicon.

These new tools yield very substantial increases in productivity if used with the modern machining stations at the high speeds for which they were developed.

The development work was accompanied by scientific studies in order to gain insights into the mechanisms underlying tool behaviour. These studies included wear at low and high temperature and chemical compatibility studies between tool material and workpiece material.