Joining
technologies

Overlay and repair with filler material

The addition of material to overlay and repair is a procedure whereby a melted material is added to a certain area or surface of a base material or substrate. In repair applications, the filler material is usually similar to the base material, while in overlay processes, a different material is used to make the substrate more resistant to wear and/or corrosion. In the latter case, the least possible dilution of filler material with the base material is sought in order to obtain a differentiated chemical composition in the weld metal.

At LORTEK two technologies are available to overlay and repair with filler material. One is laser overlay or Laser Cladding (LC) and the other is electric arc overlay. The former is a metal deposition process that uses a laser source to generate a concentrated beam that melts the material, which is dispensed through a powder feeder to the nozzle. In the second case, a controlled electric arc generates the necessary energy to melt the filler wire. In both cases, material is added through the overlapping of beads in one or several layers on a flat or 3D shaped substrate, with a high deposition rate (up to 2.5 Kg/h for laser cladding, and up to 4 Kg/h with electric arc).

These technologies permit the use of a wide variety of high-quality commercial materials in the form of powder or wire. Alongside raw material manufacturers, with which LORTEK has partnerships, suitable mechanical properties can be obtained, and sometimes it is even possible to improve the wear and/or fatigue resistance in a wide range of service temperatures and complex operating conditions. These processes also permit obtaining gradual composition or multi-material components.

One of the advantages of the laser cladding process is that it permits controlling the energy density provided and the laser beam diameter, to effectively control the heat input per unit of area, and obtain defect-free filler, with low dilution and low thermal affectation of the substrate.

On the other hand, the electric arc overlay technology is a more economical process due to the lower cost of the filler material, of the equipment, and the higher deposition rate, although the dilution level and the residual stress and distortion are much higher than that achieved by means of laser cladding.

With material overlay, the working life of components such as punches and dies, and other tools can be increased. It can also be used to make partial repairs in localized areas of large or high-value parts both during manufacture and during maintenance operations.

Depending on the final application, similar or improved mechanical properties, with respect to those of the base material, can be obtained, providing that the filler material, the process parameters and manufacturing route have been adequately selected. LORTEK’s knowledge in terms of materials, advanced characterization and process, permits 360º accompaniment for the industrial implementation of these processes. Combined with the advanced automatic non-destructive inspection techniques developed by LORTEK, this guarantees the final quality of the product and of the filler material, providing the components with enhanced functionalities.

What we are currently working on

  • Processing of new Fe-, Co- or Ni-based alloys for high temperature and/or wear-resistant and mechanical fatigue-resistant applications.
  • Repair with alloys with difficult welding properties, and that are highly susceptible to cracking.
  • Process control and monitoring that permit optimizing the deposition process in two lines of action: on-line and off-line.
  • Numerical simulations for temperature evolution, distortions and residual stress during the process.
  • Development of automated repair and overlay processes.
  • Technology industrialization and process digitalization, in line with the Industry 4.0 philosophy.
  • Performance study in repaired and overlaid parts service.

Specific Equipment

LORTEK has three solid state laser sources for laser overlay: a 6 kW disc laser, a 3kW Nd-YAG laser, and a 1kW fibre laser. It also has a semi-conductor source: a 3kW diode laser. This wide range of wavelengths and power permits processing a broad gamut of materials, using the most adequate laser for each specific application. It also has different headstocks with fixed or floating optics, which permit varying the laser spot during the process, as well as incorporating ports for on-axis sensors or camera to monitor the melted bath, or to measure the temperature. The laser beam is guided to the headstock by different diameter optical fibres.

The powder is provided through powder feeders from two heated hoppers with two types of nozzles: coaxial for standard powder, and three-jet nozzles with carbide inserts for the different applications and degrees of accessibility required. Different specialized CAM software packages are available to generate trajectories for direct deposition processes, in which the virtualization of kinematics, headstocks and nozzles, and the execution of simulations are possible.

  • 3-axis cartesian kinematic station with possibility of a fourth axis (rotary plate), comprised of a CNC table (500x500x800 mm) with Fagor 8070 control equipped with data acquisition and remote connectivity.
  • Laser overlay robotized cell comprised of a Fanuc ARC Mate 120iC robot indexed to a 2-axis Fanuc servo positioner (rotary table).

With respect to electric arc overlay equipment, LORTEK has the following equipment:

Power sources for different welding technologies

  • MIG-MAG: Fronius TPSi and Fronius Transpuls (2) with different synergic curves including CMT.
  • MIG-MAG: Fronius CMT TWIN.
  • TIG: EWM TigSpeed with cold wire and hot wire feed options, with and without oscillation.
  • Plasma: SBI with automatic wire feed.

Robotized cells

  • 6-axis KUKA KR16.
  • 1 6-axis FANUC Arcmate 120iC.
  • 1 6-axis FANUC Arcmate 120iC and 2 additional external axes.
  • 1 8-axis ABB.

CAD/CAM software

  • SKM DCAM.
  • Autodesk PowerMill Additive.

Distortion prediction and control software

  • Abaqus.
  • Own FEM-based algorithms.

Part inspection equipment

  • Ultrasounds.
  • Thermography.
  • Collaboration with 3rd parties for other tests: metrology, X-rays and computerized tomography.
  • Laser scanning and structured light systems for digitalization and metrology analysis.
  • Varestraint testbench to study hot cracking susceptibility of base materials and filler metals.

Publications and downloads

Publications

García de la Yedra, A, Pfleger, M, Aramendi, B, et al.
Online cracking detection by means of optical techniques in laser‐cladding process.
Struct Control Health Monit. 2019; 26:e2291. ISSN:1545-2263.

J.C. Pereira, J.C. Zambrano, E. Rayón, A. Yañez, V. Amigó.
Mechanical and microstructural characterization of MCrAlY coatings produced by laser cladding: The influence of the Ni, Co and Al content.

J.C. Zambrano, B. Carcel, J. C. Pereira, V. Amigó
TiAl laser cladding coatings on Ti6Al4V: Tribological characterization.
Rev. LatinAm. Metal. Mater. 2016; 36(1) 45-53. ISSN 0255-6952.

J.C. Pereira, J.C. Zambrano, M.J. Tobar, M.P. Licausi, V. Amigó.
Tribology and high temperature friction wear behaviour of MCrAlY laser cladding coatings on stainless steel, Wear
2015 (330) 280-287. ISSN 0043-1648.

J.C. Pereira, J.C. Zambrano, M.J. Tobar, A. Yañez, V. Amigó.
High temperature oxidation behavior of laser cladding MCrAlY coatings on austenitic stainless steel.
Surface & Coatings Technology, 2015 (270) 243-248. ISSN 0257-8972.
2018
Alvarez, P., Vázquez, L., García-Riesco, P. M., Rodríguez, P. P., Magaña, A., & Santos, F.
A Simplified Varestraint Test for Analyzing Weldability of Fe-Ni Based Superalloys. In Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications (pp. 849-865). Springer, Cham.
2019
Alvarez, P., Mancisidor, A. M., & Zubiri, F.
Ventajas de la tecnología de recargue láser. Soldadura y tecnologías de unión, 30(158), 22-28.
2019
Alvarez, P., Vázquez, L., Ruiz, N., Rodríguez, P., Magaña, A., Niklas, A., & Santos, F.
A Simplified Varestraint Test for Analyzing Weldability of Fe-Ni Based Superalloys. In Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications (pp. 849-865). Springer, Cham.

Success Cases

Prolonging the life of cold stamping tools

Challenge

To prolong the life of cold stamping tools.

Solution

Laser cladding with materials resistant to wear by abrasion.

Partners or strategic alliances

CIE Legazpi.

Prolonging the life of forging dies.

Challenge

To prolonging the life of forging dies.

Solution

Laser cladding with materials resistant to wear and mechanical fatigue at high temperatures.

Partners or strategic alliances

Alcorta and others.

Automation of cast parts repair processes

Challenge

Automation of cast parts repair processes.

Solution

Development of robotized arc welding installation with solutions for automatic welding.

Partners or strategic alliances

Development of robotized arc welding installation with solutions for automatic welding.

Repair of difficult-to-weld aeronautical parts

Challenge

Repair of difficult-to-weld aeronautical parts.

Solution

Comparison of laser and electric arc overlay processes, selection of filler metals.

Partners or strategic alliances

ITP, EIPC.

Repair of cast parts for railway applications

Challenge

Repair of cast parts for railway applications.

Solution

Development of electric arc filler process.

Partners or strategic alliances

CAF, ESTANDA.

Challenges

Challenges to be faced in the coming years:

Process digitalization.
Implementation of control and monitoring strategies in industrial environments.
Development of an internal or collaborative model, to test products obtained in real service conditions.

Juan Carlos Pereira, PhD.

Main researcher in LMD Additive Manufacturing and Laser Cladding.

He is the author of more than 19 peer-reviewed publications, the majority of them in high impact journals (Scopus, SCR-JCR) over the last 5 years. Several presentations at national and international congresses related to the development and characterization of MCrAIY laser coatings for high temperature applications, and also for the development of laser-based additive manufacturing processes such as LMD and SLM. He has been working at LORTEK since 2017. Prior to that, he worked as a researcher at the Institute of Material Technology (ITM, Valencia - Spain) and as Professor and Researcher in the Manufacturing Materials and Processes Department of the Engineering Faculty (UC, Valencia – Venezuela). He is currently working in the Laser Based Additive Manufacturing group at LORTEK, participating in different European, national and regional R&D projects.Project leader in HYPROCELL (H2020-FoF13-2016), Project leader in NEMARCO (H2020 CS2-CFP11-SYS-03-26) and technical support in the AMABLE project (H2020-FoF12-2017-ICT I4MS).