| Popis: |
Dimensional machining realized by laser beam and/or another concentrated energy sources in metallic targets, is based on melting, vaporisation and expulsion of some quantities of metal as a function of radiation parameters and material nature. In some cases as: drawing plates used for the synthetic wires, fine fuel filters or fuel injectors, for the internal surface of the hole, is prefered more roughness in comparison of the holes, realized by classic piercing. For instance, to realize some textures of simple synthetic fibres or in combination with natural fibres we want to have not a smooth surface, but a rough one because in this way, the texture will be more resistant in the places exposed at different efforts. Concerning the fuel injectors we prefere the same: a rough surface, in order to ensure a better pulverized jet of the fuel. In the same time, when the hole is machined with a concentrated energy: L.B.M., E.B.M. a.s.o. the injector has a longer life. It is not very easy to study the roughness resulted by L.B.M. in a less than 0.2 mm diameter hole. To avoid errors of investigation, authors have experienced on pieces of carbide and alloyed steel which were bored on separate adjacent plans, and in this way, the bored surfaces were not affected by a cutting operation after boring, for such small diameters. |
