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Key words: Laser cladding, coaxial injection.
Abstract: This paper presents a review of the laser cladding process and the main industrial applications of this technology. Laser cladding is a new, versatile technique suitable for improvement or reconditioning metallic surfaces. Proprieties like hardness, wear resistance, corrosion resistance may be enhanced through a high quality-coatings carried out by laser cladding technology. In addition the paper describe different laser cladding technique and highlights the main advantages of coaxial laser cladding process in the field of aircraft engine reconditioning.
1. INTRODUCTION
Beside the all laser process, the laser cladding is dependent on the evolution of the laser technology. In the last decade, on average, the laser power increases with 100% and new type of lasers are reported every year. In addition, the quality of the laser beam, the lifetime and the wall plug efficiency are constantly improved.
The laser cladding process takes advantage of all of these benefits. Therefore, new direction and industrial applications for material processing are possible trough laser deposition.
Nowadays the laser cladding technology may be found in automotive, petrochemical, aerospace, military and in medical application for improving or remanufacturing metallic surfaces or even to create new pieces trough the rapid prototyping technique.
The main goal of the laser cladding is to create high quality layers at the lowest possible price.
2. PROCESS DESCRIPTION
In laser cladding, the laser beam is used as a heating source and a filler material in the form of powder or wire is delivered on the surface and fused through the action of the laser beam. All of the cladding process employs a shielding gas for carrying and focus the powder and for the protection the melted bath against oxidation.
The laser cladding is highly influenced by the equipments used and the process parameters. Only the correct combination of the focusing optics, feeding devices and parameters may assure a successful cladded layer [I].
The laser cladding process may be achieved by various techniques depending mainly on the filler material type and feeding method. According to [2, 3] the most common method to supply the cladding material are:
* Preplaced powder on the substrate surfaces;
* By wire feeding;
* Powder injection with a carrier inert gas.
2.1 Laser cladding...