Illkirch-Graffenstaden, France
Illkirch-Graffenstaden, France

Time filter

Source Type

Boisselier D.,IREPA LASER | Sankare S.,IREPA LASER | Engel T.,ICube
Physics Procedia | Year: 2014

The implementation of the continuous 5-axis configuration can extend the limits of the Laser Direct Metal Deposition (LDMD) processes, especially when the complexity of the parts to be built is growing. In order to follow the profile of a part, we use the orientation of its growth axis. Although 5-axis machining is well known nowadays, LDMD processes require a specific optimization that depends on many parameters. Unlike conventional machining, it has to be noted that the speed variation tool tip affects the stability of deposition. Thus, we have to smooth trajectories in order to provide fluid movements and also to ensure the stability of deposition. This article describes the method and results in the optimization of trajectories to build metallic parts with freeform. Optical sensors have been implemented in the focusing unit in order to follow the variations of the laser-powder-substrate interaction and also to detect the process instabilities. Thanks to the right use of a new and large 5 axis machine and specific setting trajectories, manufacturing parts in 5-axis, with no concession on the construction rate has been possible. © 2014 The Authors. Published by Elsevier B.V.


De Lima M.S.F.,Institute for Advanced Studies | Sankare S.,IREPA LASER
Materials and Design | Year: 2014

Laser additive manufacturing of stainless steels is a promising process for near net shape fabrication of parts requiring good mechanical and corrosion properties with a minimal waste generation. This work focuses on high aspect ratio AISI 316 steel structures made by superposition of sequential layers. A special nozzle for precise powder delivery together with a monomode fiber laser allowed producing high quality steel stringers on AISI 316 steel substrates. Although the stringers average compositions were inside the austenite plus ferrite range, only austenite phase was verified. The cladded structure presented some internal pores and cracks, responsible by the low Young's moduli. However, the tensile properties were similar to the base material and other literature results. The three-point flexural tests also produced good results in terms of formability. The fabricated structures proved to be useful for use in mechanical construction. © 2013 Elsevier Ltd.


Serres N.,LGeCo LISS | Hlawka F.,LGeCo LISS | Costil S.,University of Technology of Belfort - Montbéliard | Langlade C.,University of Technology of Belfort - Montbéliard | MacHi F.,IREPA LASER
Journal of Materials Processing Technology | Year: 2011

This study aims at evaluating the effect of an in situ laser remelting treatment of NiCrBSi coatings, deposited by plasma spraying. Life Cycle Assessment (LCA) method was used to estimate the environmental impacts of coating processes. It was demonstrated with this LCA that the in situ remelting process was clean. Microstructural results were also evaluated. A good metallurgical bond was formed at the remelted coating interface. Scanning electron microscopy observation revealed also that laser treatment induces a change of the microstructure from lamellar to columnar dendritic. The dependence between the microstructure of NiCrBSi coatings, which was modified by laser treatment, and corrosion resistance has been evaluated by potentiodynamic polarization curves. Results show that, the corrosion resistance was increased because of a finer structure and higher densities of the coatings, but corrosion mechanisms occurring in all cases were different. From the electrochemical experiments in NaCl solution it can be deduced that laser remelting of as-sprayed coatings does not affect their corrosion rate. Corrosion evolves due to a progressive penetration of the electrolyte through the disturbed structure of the as-sprayed samples, whereas the substrate surface of remelted coating is not reached, because of a higher density. But ClMO intermediate species were formed on the surface, because Cl- can destroy the protective film on the coating. The hybrid plasma/laser process was cleaner than hard chromium plating and its corrosion behavior is superior too. © 2010 Elsevier B.V. All rights reserved.


Serres N.,LGeCo LISS | Hlawka F.,LGeCo LISS | Costil S.,University of Technology of Belfort - Montbéliard | Langlade C.,University of Technology of Belfort - Montbéliard | MacHi F.,IREPA LASER
Journal of Thermal Spray Technology | Year: 2011

This paper deals with coating alternatives to hard chromium plating. Thermal spraying is already used in industry, but results are not always satisfactory for reasons of porosity and microstructures. In this study, atmospheric plasma spraying (APS) and in situ laser irradiation by diode laser processes were combined to modify the structural characteristics of thick NiCrBSi alloy layers. The microstructure evolution was studied, and results show that in situ laser remelting induced the growth of a dendritic structure, which strongly decreased the porosity of as-sprayed coatings and increased the adhesion on the substrate. Moreover, no phase transition after laser treatment was observed. Lastly, a mechanical investigation demonstrated that the combination between plasma spray and in situ melting with a diode laser could result in very good mechanical properties. The increase of the laser incident power involved an increase of the mean contact pressure, along with coating hardness. The hybrid process appears to be a possible alternative to hard chromium plating, in order to protect mechanical parts, because of the improved mechanical properties of the NiCrBSi layer. © 2010 ASM International.


Serres N.,LGECO LISS | Hlawka F.,LGECO LISS | Costil S.,University of Technology of Belfort - Montbéliard | Langlade C.,University of Technology of Belfort - Montbéliard | Machi F.,IREPA LASER
Wear | Year: 2011

Electrolytic hard chromium has proved to be effective against wear. However, its use is about to decrease due to the toxic and carcinogenic characteristics of hexavalent chromium. A lot of promising alternatives have been already studied. Among them, thermal spraying presents a good potential. In this study, laser remelting was combined simultaneously to thermal spraying in order to modify a metal alloy coating characteristics. The mechanical properties of a nickel-base layer were investigated by nanoindentation, scratch tests, interfacial indentation and tribological ball-on-disc experiments. The influence of the coating structures on the wear behaviour of in situ remelted NiCrBSi coatings was investigated. This paper demonstrates that the remelted samples have better mechanical performances than as-sprayed coatings. Moreover, the adhesion of remelted samples was strongly increased, as well as the fracture toughness. According to the selected processing parameters, the increase of the laser energy density seems to show better mechanical results. © 2011 Elsevier B.V.


Serres N.,LGECO LISS | Hlawka F.,LGECO LISS | Costil S.,University of Technology of Belfort - Montbéliard | Langlade C.,University of Technology of Belfort - Montbéliard | Machi F.,IREPA LASER
Surface and Coatings Technology | Year: 2010

The alternative coatings to electrodeposited hard chromium plating are studied nowadays, because of the chemical composition of the baths containing Cr(VI), forbidden by several European regulations. Thermal spraying is already used in industry, but the deposited coatings still need improvements for reasons of porosity and microstructures. In this study, atmospheric plasma spraying and in situ laser irradiation by diode laser processes were combined to modify the structural characteristics of NiCrBSi coatings. The microstructure evolution was studied, with the analysis of chemical composition using energy-dispersive spectroscopy and X-ray diffraction. Results show that in situ laser remelting induces the growth of a dendritic structure which strongly decreases the porosity of as-sprayed coatings and no phase transition after laser treatment. The adopted configuration drives to the achievement of coatings without solidification cracking, one of the major defects that can occur during the solidification of metallic alloys. Furthermore, to evaluate the environmental impacts of coatings in comparison with other conventional treatments developed to melt NiCrBSi layers, a Life Cycle Assessment was carried out. The ecodesign of surface coatings has not been reported in detail in the current literature, and nowadays, life cycle analysis is an important consideration for the thermal spray community. The good environmental assessment of the hybrid process is demonstrated in this paper. © 2010 Elsevier B.V.


Patent
Irepa Laser and Asociacion De Investigacion Metalurgica Del Noroeste Aimen | Date: 2015-12-16

The present invention relates to a method of manufacturing a direct and selective surface deposition by a pulsed radiation treatment. Said method allows the production of a selective pattern on any receiving material without any pre-treatment and/or post-treatment of said receiving material. The invention provides a selective deposition of a donor material onto a receiving material by means of a pulsed radiation treatment without any contact between said donor and receiving materials. It further provides a method of direct surface metallization of various types of receiving materials using a pulsed radiation treatment. The present invention provides a method of manufacturing a direct and selective surface deposition by a pulsed radiation treatment of a donor material onto a receiving material. The present invention relates more particularly to a method of manufacturing free form patterned deposition on surfaces of various receiving materials.


Boisselier D.,IREPA LASER | Sankare S.,IREPA LASER
ICALEO 2013 - 32nd International Congress on Applications of Lasers and Electro-Optics | Year: 2013

The implementation of the continuous 5-axis configuration can push the limits of the Laser Direct Metal Deposition (LDMD) processes, particularly in terms of complexity of part to build. The inclination of the part growth axis makes it easier to follow the profile of the part. Although continuous 5-axis machining is well known nowadays, LDMD processes require a specific optimization. It depends on many parameters that need the implementation of smooth trajectories in order to ensure the deposit stability, to make more fluid movements, knowing that the speed variation tool tip affects the stability of deposition, unlike machining. IREPA LASER has developed specific tools (CLAD process) based on its patented coaxial powder cladding nozzle and a 5-axis tool path generator software called PowerCLAD. This article describes the method and results in the optimization of trajectories to build metallic parts with freeform. Optical sensors have been implemented in the focusing unit in order to follow the variations of the laser-powder-substrate interaction and to detect the process instabilities. Thanks to good utilization of a new and large 5 axis machine, the optimization of the CAD software and a specific setting trajectories, it becomes possible to manufacture parts in 5-axis, without sacrificing the construction rate.


Serres N.,LGeCo LISS | Portha N.,IREPA LASER | Machi F.,IREPA LASER
Surface and Coatings Technology | Year: 2011

NiCrBSi materials are widely used in applications where corrosion and wear resistance are required. This Ni-based alloy has been deposited onto C38 steel disc using the laser cladding technique. This paper describes the results of experiments that were performed using pin-on-disc tribometer and Knoop indentation on aging tests, for different exposure times, in a salt spray booth. Salt spray corrosion tests have shown that over 800h of exposure, samples exhibit very high corrosion resistance. Mechanical properties, as well as wear behaviour are not affected under these conditions, due to the formation of Cr2O3 on the surface. However, for longer exposure (aging) time, wear behaviour was affected because of a pit distribution as well as chlorine presence on the surface. Thus, the mechanical properties deteriorated. © 2011 Elsevier B.V.


Patent
Irepa Laser | Date: 2013-01-11

The present disclosure relates to a shaping device for light rays of a laser beam that cross it, wherein the shaping device is formed by a conduit including an entry orifice, an exit orifice, and an internal wall, achieved by one or a plurality of facets adapted to reorient by at least one reflection at least a part of the rays of the crossing beam.

Loading IREPA LASER collaborators
Loading IREPA LASER collaborators