Laser Cladding of Cobalt Alloy: Nanocomposite Coating Analysis

This report provides an overview of laser cladding of cobalt alloy, a material deposition process used to enhance corrosion resistance and material performance. The study investigates the use of nanocomposite cobalt alloy coatings through laser cladding, comparing its efficiency against conventional procedures like painting. The experiment involved using low alloyed steel S235 as a substrate, coated with a mixture of Cobalt alloy powder (Stellite 6) and ceramic nanopowders (Y2O3, ZrO2, TiC). The process includes mixing the powdered elements, transforming the powder via argon stream, and applying the mixture to the substrate using a laser beam. The results illustrate the coating of Stellite 6 on S235, the solidification of the melt pool, and detailed views of the microstructure. Observations indicate that the addition of ceramic powders produces equal nucleation, changing the microstructure and refining dendrites. The report concludes with references to relevant research and a bibliography, offering a comprehensive understanding of the laser cladding process and its applications. Desklib provides access to similar solved assignments and study tools for students.

LASER CLADDING OF COBALT ALLOY

Presented By
• Name of the Student

What is Laser Cladding?
• Cladding is a process to combine two different metals in a certain pressure and
temperature (Leyens and Beyer 2015).
• Laser Cladding is a process of material deposition in which the powdered form metal is
consolidate by laser which will provide clad to any substrate. Which helps to induce the
corrosion resistance (Abioye, McCartney and Clare 2015).

Why Laser Cladding?
According to the case study in the field of aeronautic, tooling and automotive it is essential to
enhance the performance of material surface treatment under wear and corrosion environment,
since some of the requirement cannot be addressed by the conventional procedure. This case study
has basically focused on the Nanocomposite Cobalt Alloy coating through laser cladding process.
 Fundamental objective of this study is to determine the performance efficiency of Laser
Cladding over the Conventional procedure.

Background of the Experiment
Followed by the analysis of the case study this experiment has been performed in order to
investigate the performance efficiency of laser Cladding. Thus, the aim of this experiment is to
focus on the coating process of any surface with Nanocomposition particles by laser cladding.
Previously the process of surface treatment fundamentally done by painting process.
However, the above process was efficient enough still this process was invented in order to coat
the targeted surface with high resistance to wear and corrosion in maximum temperature.

Required Equipment:
Low alloyed Steel S235 as the substrate.
Mixtures of Cobalt alloy powder (Stellite 6, 45-90 μm, Deloro) and 0.5% of Y2O3, 30-50
nm; ZrO2, 50 nm; TiC, 20 nm; IoLiTec (Ceramic nanopowders) as the predecessor layer to
be applied on the surface in order to coat the targeted area.
 Rotary ball mill Simoloyer CM01 (Zoz) was obtained in order to mix the powdered
elements with a rotation speed of 900rpm for 1200 seconds.
LDL 160-3300 direct diode laser

Composition of Cobalt Alloy and S235
Co Fe C Si Cr Mo Ni W Mn
Stellite Bal 2.25 1.15 1.38 31.0 0.25 2.39 4.50 0.48
S235 Bal 0.17 1.49

Procedure
Step 1 - Rotating the rotary ball mill Simoloyer CM01 at the speed of 900rpm for 1200 seconds the procedure of
mixing Cobalt alloy powder and the ceramic powders has been done.
Step 2 – later on the blended mixture is then poured in to a feeder.
Step 3 – Then the powder transformation was done by argon stream to the COAX 8 which is basically a coaxial
nozzle.
Step 4 – Finally the mixture was blown to the substrate by using the laser beam. The applied voltage was 3.3kW.
This process is termed as laser Cladding.

Why Stellite?
The invention of Stellite coating wsa due to the comparison of two types of laser cladding
process which includes the continuous laser power another one is in the mode of pluse laser
powder. Parameters of lasers are mentioned below:
Coating Laser voltage
(kW)
Speed (mm/s) Powder flow
(g/min)
Protection of
Gas Fllow
(1/min)
Continuous
laser+stellite 6
1350 10 8.9 14
Laser of Stellite
6
1200 9 9.4 11
Pulsed laser 1350 12 8.9 13

Result
• The below figure has illustrated the
coating of Stellite 6 in S235
• The below picture illustrates the
solidification of fast melt pool of
columnar dendrite of microstructure by
Stellite 6.

Result
This picture is illustration the upper view of
the microstructure which was coated with
Stellite 6 as well as 0.5% of Y2O3.
Detail View

Result
• This figure has provided a detail view of
the section which has been coated using
indentation

Result
• This picture has illustrate the Stellite
micrographs with 0.5% ZrO2
• Detail view

Observation
• According to the case study it has been observed that at the time of addition of ceramic
powders in to the Stellite 6 has produced equal nucleation in contact with the dendrites.
Due to the nucleation the microstructure has changes. Later on dendrites consist of
nanoparticles has become thinner and denser.
• Along with the three ceramic particles which has been used in the refinement process of
microstructure only nano-Y2O3 has a higher rate of cooling.

Observation
• Expect from the coating of ZrO2 and TiC the hardness of other coatings such as nano-
Y2O3 has the similar hardness level as Stellite 6.
• Except form the case of TiC, there was no dissolution occurred with the melted pool and
nanoparticles.

Reference
Abioye, T.E., McCartney, D.G. and Clare, A.T., 2015. Laser cladding of Inconel 625 wire for
corrosion protection. Journal of Materials Processing Technology, 217, pp.232-240.
Leyens, C. and Beyer, E., 2015. Innovations in laser cladding and direct laser metal deposition.
In Laser Surface Engineering (pp. 181-192). Woodhead Publishing.

Bibliography
Yan, C., Hao, L., Hussein, A., Young, P., Huang, J. and Zhu, W., 2015. Microstructure and mechanical properties of aluminium alloy cellular
lattice structures manufactured by direct metal laser sintering. Materials Science and Engineering: A, 628, pp.238-246.
Lin, C.K., Hsu, C.H., Cheng, Y.H., Ou, K.L. and Lee, S.L., 2015. A study on the corrosion and erosion behavior of electroless nickel and
TiAlN/ZrN duplex coatings on ductile iron. Applied Surface Science, 324, pp.13-19.
Moujaes, E.A., Aguiar, L.V. and Ghantous, M.A., 2017. Magnetization of ultrathin [Fe1− cNic] n alloy nanojunctions between Fe or Co leads
using an Ising EFT-MFT model. Journal of Magnetism and Magnetic Materials, 423, pp.359-372.
Fernández, M.R., García, A., Cuetos, J.M., González, R., Noriega, A. and Cadenas, M., 2015. Effect of actual WC content on the reciprocating
wear of a laser cladding NiCrBSi alloy reinforced with WC. Wear, 324, pp.80-89.
Liu, Z., Jiang, Q., Li, T., Dong, S., Yan, S., Zhang, H. and Xu, B., 2016. Environmental benefits of remanufacturing: A case study of cylinder
heads remanufactured through laser cladding. Journal of Cleaner Production, 133, pp.1027-1033.
Olakanmi, E.O., Cochrane, R.F. and Dalgarno, K.W., 2015. A review on selective laser sintering/melting (SLS/SLM) of aluminium alloy
powders: Processing, microstructure, and properties. Progress in Materials Science, 74, pp.401-477.
He, D., Zhang, L., He, D., Zhou, G., Lin, Y., Deng, Z., Hong, X., Wu, Y., Chen, C. and Li, Y., 2016. Amorphous nickel boride membrane
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Pusavec, F., Deshpande, A., Yang, S., M'Saoubi, R., Kopac, J., Dillon Jr, O.W. and Jawahir, I.S., 2015. Sustainable machining of high
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