Method for producing a surface-alloyed cylindrical, partially cylindrical or hollow cylindrical component and a device for carrying out said method

The method according to one of the preceding claims, characterised in

• that the energy beam is split before the zone of incidence where a first part beam is deflected into the heating zone and melting zone and a second part beam is deflected behind the solidification front for thermal structural treatment.

The method according to one of the preceding claims, characterised in

• that a ≧3 kW diode laser with a variable optical system to adjust the linear focal width of 4-15 mm is used to form the energy beam.

The method according to one of the preceding claims, characterised in

• that before the beginning and at the end of a coating the linear focal width of the energy beam and the quantity of powder is reduced transverse to the feed direction.

The method according to one of the preceding claims, characterised in

• that the workpiece is constructed as a hollow cylinder and rotates about the energy beam in the downhand position during the coating whereby the energy beam which is held in a fixed position relative to the direction of rotation, achieves a continuous feed movement during the rotation in the direction of the axis of rotation to produce a flat alloying zone.

The method according to one of the preceding claims, characterised in

• that at the beginning of alloying the energy beam has a point structure and continually increases in size together with the quantity of powder until it has reached the complete linear focal width after a rotation of the workpiece.

The method according to one of the preceding claims, characterised in

• that at the end of the alloying during the last rotation of the workpiece the linear focal width and the quantity of powder are continuously reduced to zero.

The method according to one of the preceding claims, characterised in

• that a hollow cylinder made of Al or Mg alloys having a bore diameter of 60-120 mm is treated at a depth of up to 200 mm.

A device for implementing the method, consisting of a workpiece clamping device (1), on which a workpiece is aligned and clamped above index holes and/or above working surfaces, onto whose surface a powder supply (5) and a focusable beam from a beam head (4) are directed,

• characterised by an energy beam and powder supply device inserted into an axis of the cylinder, where the energy beam is directed as a linear focus onto the workpiece rotating in the downhand position at an angle ±a=0-45° to the gravity vector.

The device according to one of the preceding claims, characterised in

• that the energy beam units next to one another sweep several lines of the working surface simultaneously, if necessary with several powder supply devices.

The device according to one of the preceding claims, characterised in

• that the energy beam unit is located in a fixed position relative to the direction of rotation inside the rotatable workpiece clamping device connected to a drive unit where the energy beam is directed from the energy beam head onto the workpiece surface,
• that the powder supply device is located beside the energy beam device.

The device according to one of the preceding claims, characterised in

• that the powder is blown onto surface facing the beam either in the direction opposite to the feed direction through the beam into the melting zone or is sprinkled loosely in the direction of gravity before or in the melting zone in front of the energy beam.

The device according to one of the preceding claims, characterised in

• that the drive unit for the workpiece makes it possible to achieve a variable rotation speed where the feed direction of the energy beam device and the powder supply in the direction of the axis of rotation are combined with the rotation speed of the workpiece to achieve spiral or other geometrical guidance of the linear focus onto the workpiece surface.

The device according to one of the preceding claims, especially for engine blocks, consisting of a rotatable clamping device (1) for a cylinder block (2), a laser treatment unit (3) with a beam head (4), which is connected to a powder supply device (5), and a transfer unit which positions the cylinder block (2) in front of the laser beam treatment unit (3) and a drive (6) to move the transfer unit along a transfer axis (10), characterised in

• that the clamping plane of the clamping device (1) is aligned perpendicular to the beam direction of the laser unit (3),
• that the laser unit (3) can be displaced perpendicular to the clamping plane of the clamping device (1) where the beam direction is perpendicular to the transfer axis (10) at an angle ±=0 to 45° to the gravity vector,
• that the powder supply (5) either opens directly in the beam direction of the laser unit (3) or (seen in the feed direction) shortly before the beam incidence zone (12).

The device according to one of the preceding claims, characterised in

• that a laser treatment unit (3) consists of several beam devices which can be inserted in a cylinder bore whereby several working surfaces are arranged on the cylinder wall (seen in the direction of the cylinder axis).

The device according to one of the preceding claims, characterised in

• that the powder supply device (5) consists of several feed devices which can be inserted in a cylinder bore where the feed openings are arranged one behind the other (seen in the direction of the cylinder axis).

The device according to one of the preceding claims, characterised in

• that the powder supply device consists of a screw conveyor, a conveyor belt or a vibrating conveyor chute.