1. Method for treating a surface of at least one part having multiple faces with a non-uniform plasma generated with elementary plasma sources by distributed electron cyclotron resonance, comprising: subjecting the at least one part to at least one movement of revolution with regard to at least one fixed linear row of spaced apart elementary plasma sources, each source comprising a coaxial waveguide and an end fitting containing a magnet for electron cyclotron resonance, setting spacing between adjacent sources of the at least one fixed linear row between a minimum distance of about twice a diameter of the magnet, and a maximum distance Dmax determined by the formula:
D
\u2062
\u2062
max
=
2
\u2062
R
\u2062
\u2062
max
o
\u2062
P
o
P
where: R maxo is about 5 cm, Po is 2.10\u22123 mbar, and P is working pressure in mbar, the at least one fixed linear row of elementary plasma sources being disposed parallel to an axis of revolution of the at least one part and providing uniform treatment in volume of the at least one part although the plasma itself is not uniform in volume, whereby uniform surface treatment on the multiple faces of the at least one part is realized without requiring modification of equipment geometry according to geometry of the at least one part.
2. The method according to claim 1, wherein the movement of revolution is a single rotation.
3. The method according to claim 1, wherein the movement of revolution is a single or double planetary movement.
4. The method according to claim 1, wherein adjacent elementary sources have a same polarity.
5. The method according to claim 1, wherein magnetisation axis of the magnet is colinear with an axis of the waveguide and preserves symmetry of revolution of said guide and guarantees that electron paths close upon themselves.
6. The method according to claim 1, wherein the elementary sources are supplied by a single generator having a power divided into equal parts between the sources.
7. The method according to claim 1, wherein the elementary sources are supplied by generators having a power that is adjusted to have a uniform treatment along the row of the said sources.
8. The method according to claim 1, wherein minimum distance from the sources to the at least one part is the closest distance during the movement and is between 40 and about 160 mm.
9. The method according to claim 1, wherein the at least one fixed linear row of spaced apart elementary plasma sources comprises at least three elementary plasma sources.
10. The method according to claim 1, wherein the at least one fixed linear row of spaced apart elementary plasma sources consists of a single row.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
We claim:
1. A process for producing a wear-resistant, tribological cylinder bearing surface for a piston running in a cylinder of a crankcase of an internal-combustion engine, the process which comprises:
positioning a laser such that a longitudinal axis of the laser is substantially coaxial to a cylinder of a crankcase of an internal-combustion engine;
rotating the laser about the longitudinal axis of the laser and simultaneously advancing the laser in a direction of the longitudinal axis of the laser;
feeding a powdery material through the laser and directing a jet of the powdery material to a cylinder bearing surface of the cylinder;
deflecting a laser beam to an impact region where the jet of the powdery material impinges on the cylinder bearing surface and guiding the jet of the powdery material such that at least part of the jet of the powdery material passes through the laser beam; and
at least partially melting, with the laser beam, a surface of the impact region such that the surface of the impact region is at least partially melted before the powdery material impinges on the surface of the impact region.
2. The process according to claim 1, which comprises forming given structures in the cylinder bearing surface by using an additional laser treatment.
3. The process according to claim 1, which comprises forming oil pockets in the cylinder bearing surface by using an additional laser treatment.
4. The process according to claim 1, which comprises using, as the powdery material, at least one material selected from the group consisting of a silicon-containing material, a tungsten-containing material and a nickel-containing material.
5. The process according to claim 1, which comprises adjusting a laser energy such that the powdery material, which passes through the laser beam and is transported in the jet, is deposited on the cylinder bearing surface.
6. The process according to claim 1, which comprises adjusting a laser energy such that the powdery material, which passes through the laser beam and is transported in the jet, is alloyed into the cylinder bearing surface.
7. The process according to claim 1, which comprises adjusting a laser energy such that the powdery material, which passes through the laser beam and is transported in the jet, is alloyed into the cylinder bearing surface and is deposited on the cylinder surface.
8. The process according to claim 1, which comprises selecting a given rotational speed for the step of rotating the laser about the longitudinal axis of the laser, selecting a given translational speed for the step of advancing the laser in the direction of the longitudinal axis of the laser and selecting a given laser energy such that the powdery material is deposited with a layer thickness of substantially 800 m to 1000 m.
9. The process according to claim 1, which comprises selecting a given rotational speed for the step of rotating the laser about the longitudinal axis of the laser, selecting a given translational speed for the step of advancing the laser in the direction of the longitudinal axis of the laser and selecting a given laser energy such that the powdery material is alloyed into the cylinder bearing surface with a penetration depth of substantially 250 m and such that at the same time the powdery material is deposited with a layer thickness of substantially 250 m.
10. The process according to claim 1, which comprises operating the laser with a laser energy of substantially 2 kW.
11. The process according to claim 1, which comprises advancing the laser such that the laser passes only once through the cylinder for performing operating steps.
12. The process according to claim 1, which comprises advancing the laser such that the laser passes several times through the cylinder for performing operating steps.
13. A device for producing a wear-resistant, tribological cylinder bearing surface in a cylinder of a crankcase of an internal-combustion engine, comprising:
a laser for providing a laser beam;
a powder feed device extending trough said laser;
said powder feed device being configured to guide a jet of a powdery material through the laser beam and to guide the jet of the powdery material to an impact region on a cylinder bearing surface where the powdery material impinges on the cylinder bearing surface; and
a beam-deflecting device operatively connected to said laser, said beam-deflecting device deflecting the laser beam onto the impact region where the powdery material impinges on the cylinder bearing surface.
14. The device according to claim 13, wherein said beam-deflecting device includes at least one optical device selected from the group consisting of a mirror, a lens system and optical fibers.
15. In combination with a crankcase having a cylinder, a device for producing a wear-resistant, tribological cylinder bearing surface in the cylinder, comprising:
a laser for providing a laser beam, said laser being positioned coaxial with respect to the cylinder;
a powder feed device extending trough said laser;
said powder feed device being configured to guide a jet of a powdery material through the laser beam and to guide the jet of the powdery material to an impact region on a cylinder bearing surface where the powdery material impinges on the cylinder bearing surface; and
a beam-deflecting device operatively connected to said laser, said beam-deflecting device deflecting the laser beam onto the impact region where the powdery material impinges on the cylinder bearing surface.
16. The device according to claim 15, wherein said beam-deflecting device includes at least one optical device selected from the group consisting of a mirror, a lens system and optical fibers.