Sandvik Ab

Other

Mats Sj&ouml;strand

Klaus Goedicke

Siegfried Schiller

Fred Fietzke

Olaf Zywitzki

Bj&ouml;rn Ljungberg

Viveka Alfredsson

Tomas Hilding

Torbj&ouml;rn Selinder

Christian Strondl

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 relates to a process for producing a coated cutting tool consisting of a coating and a substrate, wherein at least one refractory layer consisting of fine-grained, crystalline &ggr;-Al O is deposited by reactive magnetron sputtering onto the moving substrate in a vacuum by pulsed magnetron sputtering in a mixture of a rare gas and a reactive gas at a pulse frequency set for 10 to 100 kHz. The deposition occurs with a rate of at least 1 nm/s with reference to a stationarily arranged substrate at a magnetron target power density in time average set for at least 10 W/cm . The substrate temperature is in the range 400 to 700&deg; C. and the flux of impinging particles onto each individual substrate is cyclically interrupted.

Method of making a 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.

There is disclosed a cutting tool comprising a body of a sintered cemented carbide or cermet, ceramic or high speed steel on which at least on the functioning parts of the surface of the body, a thin, adherent, hard and wear resistant coating is applied. The coating comprises a laminar structure of refractory compounds in a polycrystalline, repetitive form, (MLX/Al,O,)/(MLX/Al,O,)/(MLX/Al,O,)/(MLX/Al,O,)/ . . . , where the alternating sublayers consist of metal nitrides (or carbides) and crystalline alumina of the alpha (&agr;)- and/or the gamma (&ggr;) phase, preferably of metal nitrides and crystalline alumina of the gamma phase, and in said coating the sequence of individual layer thicknesses has no repeat period but is essentially aperiodic throughout the entire multilayered structure. The metal elements in the layers MLX are selected from Ti, Nb, Hf, V, Ta, Mo, Zr, Cr, W, Al and mixtures thereof. The total thickness of said multilayered coating is between 0.5 and 20 &mgr;m.

Multilayered PVD coated cutting tool

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.

Growing community of inventors

Kista, Sweden

Mats Sjöstrand

Growing community of inventors

Kista, Sweden

Mats Sj&ouml;strand

Mats Sjöstrand