Abstract: A method for coating by thermal spraying a substrate for solar applications with a temperature-resistant and high-absorbance ceramic micro-structured coating includes the following steps: preparing a powder mixture including ceramic microparticles powder and polyester microballs powder, a percentage of the polyester microballs in the powder mixture being between 10 and 30% w/w; spraying the powder mixture onto the substrate by a thermal spray process in order to apply a coating layer on the substrate; and heating the substrate having the coating layer to a temperature of at least 400° C. so as to evaporate the microballs of polyester from the coating layer, leaving porosities at a place of the polyester microballs. Parameters of the spraying step and particle size are chosen so that the coating layer is applied in a thickness of between 50 and 150 microns.

Abstract: A continuous electrolytic deposit of constant thickness is formed on a moving substrate (2) constituting a cathode passing in adjacent spaced relation to an anode (3) to provide a narrow electrolysis gap therebetween. The anode consists of a plurality of anode modules (3) which are supported mechanically independent of each other. The electrical and hydraulic circuits respectively feeding the anode modules include flexible sealing members (8, 11, 12, 14) between the fixed sources of current and electrolyte respectively and the anode modules. The anode modules are provided with supports (4, 9, 10) whereby they are supported on the cathode (2) or on a surface (1) directly linked to the cathode. The support for at least one anode module (3) may be adjustable for adjusting the distance between the anode module and the cathode. The supports (4) are shoes or rollers, for example, which may be mounted at the ends of arms (9, 10) supporting the anode modules.

Abstract: The surface of a rolling mill roll is coated with a coating comprising a metallic substance and is then marked by means of an intermittent laser beam. As a result, micro-craters are formed which penetrate the roll and which have rims containing components from the roll and the coating. The longevity of the roughness of the roll can thereby be enhanced.

Abstract: An apertured rotary member intermittently intercepts a laser beam directed at a given zone of a target. The apertures have inclined lateral walls which, during interception of the beam, deflect at least part of it to a further zone of the target.

Abstract: In order to improve the surface characteristics of steel structure, it is oposed according to the invention to make at least one roll of a rolling-mill with a motif or pattern of motifs. The invention also includes apparatus for marking the roll which includes means for driving the roll marking device itself from the roll so that proper synchronization between the movements of the roll and marking device is achieved.

Abstract: A continuous beam from a laser is divided into two intermittent beams by a reflecting disc with peripheral holes, rotating about an axis skew to the continuous beam. At least one of the intermittent beams is transmitted to a marking head having a lens which focuses the beam onto the surface of a roll. The roll is rotated and the marking head is moved along the roll, in synchronism with the rotation of the disc, so that a regular hexagonal lattice of microcavities is cut by the focused intermittent beam. The second intermittent beam may be used to cut microcavities in the roll or in a second roll or for other purposes.