Other

Sandvik Ab

Viveka Alfredsson

Klaus Goedicke

Siegfried Schiller

Fred Fietzke

Olaf Zywitzki

Bj&ouml;rn Ljungberg

Mats Sj&ouml;strand

Tomas Hilding

The present invention describes a coated cutting tool for metal machining. The coating is formed by one or more layers of refractory compounds of which at least one layer of fine-grained, crystalline &ggr;-phase alumina, Al O , with a grainsize less than 0.1 &mgr;m. The Al O layer is deposited with a bipolar pulsed DMS technique (Dual Magnetron Sputtering) at substrate temperatures in the range 450&deg; C. to 700&deg; C. preferably 550&deg; C. to 650&deg; C., depending on the particular material of the tool body to be coated. Identification of the &ggr;-phase alumina is made by X-ray diffraction. Reflexes from the (400) and (440) planes occurring at the 2&thgr;0- angles 45.8 and 66.8 degrees when using Cu radiation identify the &ggr;-phase Al O . The alumina layer is also very strongly textured in the &lsqb;440&rsqb;-direction. The Al O layer is virtually free of cracks and halogen impurities. Furthermore, the Al O layer gives the cutting edge of the tool an extremely smooth surface finish.

PVD Al2O3 coated cutting tool

The present invention describes a coated substrate material. The coating is formed by one or more layers of refractory compounds of which at least one layer of fine-grained, crystalline &ggr;-phase alumina, Al O , with a grainsize less than 0.1 &mgr;m. The Al O layer is deposited with a bipolar pulsed DMS technique (Dual Magnetron Sputtering) at substrate temperatures in the range 450&deg; C. to 700&deg; C., preferably 550&deg; C. to 650&deg; C., depending on the particular substrate material. Identification of the &ggr;-phase alumina is made by X-ray diffraction. Reflexes from the ( ) and ( ) planes occurring at the 2&thgr;-angles 45.8 and 66.8 degrees when using Cu radiation identify the &ggr;-phase Al O . The alumina layer is also very strongly textured in the &lsqb;440&rsqb;-direction. The Al O layer is virtually free of cracks and halogen impurities. Furthermore, the Al O layer gives the cutting edge of the tool an extremely smooth surface finish.

The present invention describes a coated cutting tool for metal machining. The coating is formed by one or more layers of a refractory compound of which at least one layer of fine-grained, crystalline &ggr;-phase alumina, Al,O,, with a grain size of less than 0.1 &mgr;m. The Al,O,layer is deposited with a bipolar pulsed DMS technique (Dual Magnetron Sputtering) at substrate temperatures in the range 450&deg; C. to 700&deg; C., preferably 550&deg; C. to 650&deg; C., depending on the particular material of the tool body to be coated. Identification of the &ggr;-phase alumina is made by X-ray diffraction. Reflexes from the (,) and (,) planes occurring at the 2&thgr;-angles 45.8 and 66.8 degrees when using Cu,radiation identify the &ggr;-phase Al,O,. The alumina layer is also very strongly textured in the &lsqb;(,)&rsqb;-direction. The Al,O,layer is virtually free of cracks and halogen impurities. Furthermore, the Al,O,layer gives the cutting edge of the tool an extremely smooth surface finish.

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Lund, Sweden

Viveka Alfredsson