Sandvik Intellectual Property Ab

Leif Dahl

Gerold Weinl

Ulf Rolander

Mikael Lindholm

Jeanette Persson

The present invention relates to a cutting tool insert preferably for machining of hardened steel, hot and cold working tool steel, die steel, case hardened steel, high speed steel and ductile grey cast iron and composed of a composite comprising from about 30 to less than about 60 vol-% of a cBN-phase and a binder phase comprising a titaniumcarbonitride phase and a TiBphase. According to the invention, in the XRD pattern from the composite using CuK&#x3b1;-radiation the peak height ratio of the strongest TiBpeak and the strongest cBN peak is less than about 0.02.

Cutting tool insert

Method of producing a sintered body comprising the steps of mixing one or more powders forming hard constituents with powders forming a binder phase comprising cobalt powder where the cobalt powder comprises cobalt having mainly a fcc-structure defined as the peak height ratio between the Co-fcc(200)/Co-hcp(101) being greater than or equal to about 3/2, as measured between the baseline and maximum peak height, measured by XRD with a 2&#x3b8;/&#x3b8; focusing geometry and Cu-K&#x3b1; radiation. The present invention also relates to a ready-to-press powder comprising cobalt having mainly a fcc-structure and where the cobalt powder has a grain size (FSSS) of from about 0.2 to about 2.9 &#x3bc;m. The present invention also relates to sintered bodies made according to the method. The sintered bodied according to the present invention have reduced porosity and less crack formation.

Method of making a sintered body, a powder mixture and a sintered body

A cutting tool insert which can, for example, be used for machining of hardened steel, hot and cold working tool steel, die steel, case hardened steel, high speed steel and ductile grey cast iron and composed of a composite comprising a cBN-phase and a binder phase comprising a titaniumcarbonitride phase and a TiBphase is disclosed. In the XRD pattern from the composite using CuKa-radiation, the peak height ratio of the strongest (101) TiBpeak and the strongest cBN (111) peak is less than about 0.06, the (220) from the titanium carbonitride phase in the XRD-pattern intersects both vertical lines of the PDF-lines of TiC (PDF 32-1383) and TiN (PDF 38-1420) and the lowest intersected point height is at least about 0.15 of the maximum (220) peak height of the ceramic binder phase. The insert is made by powder metallurgical methods milling, pressing and sintering, the sintering being performed at lowest possible temperature for shortest possible time necessary to obtain a dense structure.

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Hägersten, Sweden

Leif Dahl