Sandvik Ab

Nils G Brandt

Anders G Thelin

Zeljka D Senesan

Ake B Byhlin

The present invention relates to a ceramic whisker-containing cutting insert for chipforming machining of steel having improved mechanical, thermal and wearing properties. Besides an oxide-based matrix, the material contains 5-50, preferably 10-40, % by volume of homogeneously distributed whiskers or platelets of nitrides, carbides and/or borides of metals from group IVB (Ti, Zr or Hf) and/or VB (V, Nb or Ta) in the periodic system (or solid solutions thereof) having a linear expansion coefficient being lower than that of Al.sub.2 O.sub.3, preferably at the most 85% of that for Al.sub.2 O.sub.3 measured at 300-1300K. The properties of the composite material can be further modified by coating the whisker material with thin layers. The whisker reinforced cutting tool material shows an improved toughness behavior.

Whisker-reinforced ceramic cutting tool material

The present invention relates to a ceramic whisker-containing cutting insert for chipforming machining of steel having improved mechanical, thermal and wearing properties. Besides an oxide-based matrix, the material contains 5-50, preferably 10-40, % by volume of homogeneously distributed whiskers or platelets of nitrides, carbides and/or borides of metals from group IVB (Ti, Zr or Hf) and/or VB (V, Nb or Ta) in the periodic system (or solid solutions thereof) having a linear expansion coefficient being lower than that of Al.sub.2 O.sub.3, preferably at the most 85% of that for Al.sub.2 O.sub.3 measured at 300-1300 K. The properties of the composite material can be further modified by coating the whisker material with thin layers. The whisker reinforced cutting tool material shows an improved toughness behavior.

This invention relates to a cutting tool material with improved toughness behavior using alumina or silicon nitride as the matrix material. The improved toughness is achieved by the addition of whiskers and optionally zirconia in a monoclinic or tetragonal phase, to the matrix. The whiskers are disc-shaped with a thickness of 0.5-8 .mu.m and an equivalent diameter (hypothetical diameter of a circle with the same area as the disc) of about 5-50 .mu.m.

Ceramic cutting tool material with improved toughness

A ceramic cutting insert including whiskers for chip forming machining of steel and having improved mechanical, thermal and wear properties. The insert comprises an oxide based matrix and 5-50% by volume, preferably 10-40% by volume, of homogeneously dispersed whiskers of a solid solution of nitride and oxide of aluminum, preferably of the cubic aluminum oxynitride spinel (AlON). A part of the whiskers constituent may be replaced by whiskers of silicon carbide. The properties of the composite material can be further modified by coating the whisker material with thin layers. The whisker reinforced cutting material shows an improved toughness behavior compared to non-whisker containing ceramic materials.

Ceramic cutting material reinforced by whiskers

This invention relates to a cutting tool material with improved toughness behavior. The improved toughness behavior is obtained by using carefully selected reinforcing materials. The objectives of this invention are realized by simultaneously utilizing additives resulting in different toughenings mechanisms. By the simultaneous utilization of different toughening additives, synergistic effects occur giving the tool excellent material properties. The tool material of the present invention comprises reinforcing whisker additives of one dimensional single crystals with preferably different diameter and aspect ratios, two dimensional single crystals with different thickness and aspect ratios, and, in combination therewith, phase transformation additives such as ZrO.sub.2.

Method of cutting with ceramic cutting tool having improved toughness

The present invention relates to a cemented carbonitride alloy in which the toughness has been improved by the incorporation in the structure of whiskers of nitrides, carbides and/or carbonitrides of titanium, zirconium and/or hafnium.

Cemented carbonitride alloy with improved toughness behaviour

The present invention relates to an alloy for cutting tools comprising 75-97 % by weight of a hard carbonitride component and 3-25 % by weight of a binder metal, the hard component comprising titanium as the main metallic component besides tungsten, molybdenum, tantalum and optionally vanadium and as non metallic components carbon and nitrogen. The binder metal is selected from the group consisting of iron, cobalt and nickel. The plastic deformation resistance of the alloy has been improved by adding tantalum as a mixed carbide (Ti,Ta)C possibly also including Nb.

Cemented carbonitride alloy with improved plastic deformation resistance

The present invention relates to a ceramic cutting insert containing whiskers for chip forming machining of steel and having improved mechanical, thermal and wear properties. The insert comprises besides the oxide-based matrix 5-50% by volume, preferably 10-40% by volume, of homogeneously dispersed whiskers of carbides, nitrides and/or borides of titanium and/or zirconium and, where applicable, solid solutions thereof. A part of the whiskers may be replaced by whiskers of silicon carbide. The properties of the composite material can be further modified by coating the whisker material with thin layers. The whiskers reinforced cutting material shows an improved toughness behaviour and resistance to thermal crack formation without having a negative influence on the wear resistance to any appreciable extent.

Ceramic cutting tool reinforced by whiskers

The present invention relates to an alloy for cutting tools comprising 75-97% by weight of a hard carbonitride component and 3-25% by weight of a binder metal, the hard component comprising titanium as the main metallic component besides tungsten, molybdenum, tantalum and optionally vanadium and as non metallic components carbon and nitrogen. The binder metal is selected from the group consisting of iron, cobalt and nickel. The plastic deformation resistance of the alloy has been improved by adding tantalum as a mixed carbide (Ti,Ta)C possibly also including Nb.

This invention relates to a cutting tool material with improved toughness behavior. The improved toughness behavior is obtained by using carefully selected reinforcing materials. The objectives of this invention are realized by simultaneously utilizing additives resulting in different toughening mechanisms. By the simultaneous utilization of different toughening additives, synergistic effects occur giving the tool excellent material properties. The tool material of the present invention comprises reinforcing whisker additives of one dimensional single crystals with preferably different diameter and aspect ratios, two dimensional single crystals with different thickness and aspect ratios, and, in combination therewith, phase transformation additives such as ZrO.sub.2.

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Solna, Sweden

Nils G Brandt