Sumitomo Electric Industries, Limited

Akito Yoshida

Kazuwo Tsuji

Nobuo Urakawa

Shuichi Satoh

Shuji Yazu

Yutaka Kobayashi

Katsuyuki Tanaka

Kazuo Tsuji

A synthetic single crystal diamond for wire drawing die; the process of manufacturing it and a wire drawing die to utilize it are disclosed. At least one plane of the diamond for wire drawing die is a cleavage plane of (111) faces, and the drawing hole of wire drawing die lies vertical to the cleavage plane. The diamond for the wire drawing die is produced by providing a synthetic single crystal having 20-400 ppm nitrogen of Ib type diamond. A groove is made on the diamond surface parallel to (111) faces employing energy beams such as a laser beam, an ion beam and an electron beam. A wedge is struck into the groove to cleave the diamond, and a plate is obtained. Furthermore, the plate is divided into polyhedrons, employing either an energy beam or a blade. The cleavage plane of the polyhedron is almost parallel to the (111) faces of crystal, therefore the cleavage plane is used as the standard plane to build the drawing hole.

Synthetic single crystal diamond for wiring drawing dies and process for

A diamond dresser having a long life and excellent wear resistance includes at least one diamond tip. An end surface of the diamond tip perpendicular to its longitudinal direction is formed by a {211} crystal plane. Two opposite side surfaces of the diamond tip extending along the longitudinal direction are formed by {111} crystal planes. The present crystal orientation of surfaces of the tip allows each tip to be embedded in a tip holder body on a flat plane while maintaining optimum alignment with respect to the most wear-resistant direction.

Single-crystalline diamond tip for dresser and dresser employing the same

Synthetic single crystal diamond for wire drawing dies

A diamond tool, e.g., cutting tool, dresser, wire drawing die, etc., having excellent wear resistance, heat resistance and oxidation resistance and with an improved tool life is provided, which is mainly composed of a synthetic diamond single crystal containing boron or boron and nitrogen.

Diamond tool

A diamond synthesizing method carried out under diamond-stable superhigh pressure and temperature by employing a synthesizing vessel (10) having a plurality of synthesizing chambers (10a, 10b) divided by a partition layer (16) in the vertical direction. Solvent metals (13a, 13b) respectively placed in the upwardly arranged synthesizing chamber (10a) and the downwardly arranged synthesizing chamber (10b) are prepared so that the solvent metals are different in eutectic temperature with carbon from each other. In the respective synthesizing chambers (10a, 10b), carbon sources (12a, 12b) are placed in contact with highest-temperature portions of the respective solvent metals (13a, 13b) and seed crystals (11a, 11b) are placed in contact with lowest-temperature portions thereof. The synthesizing vessel (10) is provided with a temperature gradient in such directivity that the upper part thereof is at a higher temperature and the lower part is at a lower temperature.

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Hyogo, Japan

Akito Yoshida