Process for the orientation of single crystals for cutting in a cutting machine and device for practicing this process

A process for orienting a single crystal in a cutting machine along a predetermined cutting plane (y", z") by means of a positioning device outside the cutting machine according to a predetermined orientation relative to a cutting support, the process comprising the steps of:

• positioning the single crystal on support and rotating means of the positioning device, the support and rotating means being adapted to rotate the single crystal through an angle of at least 180.degree. about a first axis of rotation included in a reference plane corresponding to a working plane (x'", y'") of the cutting machine perpendicular to its sawing plane (y'", z'") and adapted to support the crystal in such a manner that a geometric axes (x) corresponding to the principal axis of elongation of a geometric shape (x, y, z) of the single crystal corresponds with said first axis of rotation;
• determining the orientation of the cutting plane (y", z") of the single crystal relative to the crystal lattice axes (x',y',z');
• determining the orientation of the crystal lattice axes (x',y',z') relative to the geometric shape axes (x, y, z,) of the single crystal;
• determining first and second angles of rotation (d, g) having regard for the orientation of the cutting plane (y", z") relative to the crystal lattice axes (x', y', z') and relative to the geometric shape axes (x, y, z) of the single crystal;
• rotating the single crystal through said first angle (d) about said geometric axis (x) to bring the normal (x") to the cutting plane (y", z") of the single crystal into said reference plane;
• effecting a relative rotation between the cutting support and the single crystal through said second angle (g) about a second axis (z'") perpendicular to said reference plane such that the normal (x") to the cutting plane (y", z") will be oriented in a reference direction corresponding to the normal to the sawing plane (y'", z'") of the machine, said geometric axis (x) and the normal (x") to the cutting plane of the single crystal (2) lying in said reference plane, such that the single crystal may be secured with its principal axes of elongation parallel to the cutting support;
• securing the single crystal in said predetermined orientation on the cutting support whose emplacement in the cutting machine is geometrically defined relative to the sawing plane (y'", z'") of the machine;
• and
• placing the cutting support after securement of the single crystal thereto, in the cutting machine to obtain said predetermined orientation of the single crystal in the cutting machine.