Ceramics cutting tools
Ceramics, as a class of materials, have always had potential as cutting tools. They are hard, retain their hardness at high temperatures and have a relatively low reactivity with steel. Hence they can be used at high cutting speeds without deformation or dissolution wear processes determining tool life. The drawback to ceramics as tool materials is that they lack toughness and resistance to both mechanical and thermal shock; this has limited the use of ceramic tool materials in the past. In recent years there have been significant developments in ceramic tool materials; there are three categories available, namely pure oxide ceramic, mixed oxide plus carbide & nitride and silicon nitride based material.
Ceramic materials have been used in the cutting industry for over 100 years. Ceramic cutting tools are constructed mainly from alumina (Al2O3) and silicon nitride (SiN). Recent advances have also introduced the use of silicon carbide (SiC) and ceramic matrix composites (CMCs) in order to enhance the performance of the cutting tool.
There are a range of ceramic grades available for a variety of applications.
Oxide ceramics are aluminium oxide based (Al2O3), with added zirconia (ZrO2) for crack inhibition. This generates a material that is chemically very stable, but which lacks thermal shock resistance.
Mixed ceramics are particle reinforced through the addition of cubic carbides or carbonitrides (TiC, Ti(C,N)). This improves toughness and thermal conductivity.
There are our ceramic grades: IWC20, IBC20, IBC30, IBC90, ICC30, ICC90.
Whisker-reinforced ceramics use silicon carbide whiskers (SiCw) to dramatically increase toughness and enable the use of coolant. Whisker-reinforced ceramics are ideal for machining Ni-based alloys. There are our whisker ceramics grades: IW10, IW40, IW80.
Silicon nitride ceramics (Si3N4) represent another group of ceramic materials. Their elongated crystals form a self-reinforced material with high toughness. Silicon nitride grades are successful in grey cast iron, but a lack of chemical stability limits their use in other workpiece materials.
There are our silicin nitride grades: ISN40, ISN50, ISN85, ISN90.
Sialon (SiAlON) grades combine the strength of a self-reinforced silicon nitride network with enhanced chemical stability. Sialon grades are ideal for machining heat resistant super alloys (HRSA). There are our SiAlON grades: ISA75, ISA80, ISA85, ISA90.