Print ISSN: 1681-6900

Online ISSN: 2412-0758

Author : Al- khalaq Fawzy Hamood, Abd

Using of Pulsed Nd-Yag Laser in the Treatment of Thermal Spray by Aluminum and Diffusion Coating Phases of Low Alloy Steel

Abd Al- khalaq Fawzy Hamood

Engineering and Technology Journal, 2012, Volume 30, Issue 2, Pages 222-237

High power pulsed Neodymium doped Yttrium Aluminum Garnet-
(Nd– YAG)- laser with 1J power was used to fuse coatings containing a mixture of
FeAlO and Al. This mixture produced by aluminizing pack cementation treatment
and thermal spray of low alloy steel, That is for Studying the mechanical ,
surface and metallurgical properties for each coating system , and to make a
comparison before and after irradiation , and also the specified properties including
the coating thickness . Aluminum Coated samples were made by two advanced
techniques pack cementation and thermal spray methods in order to compare the
resulted coating layer properties before and after irradiation, and also to determine
the technique role from one hand ,also fusing effect and thermal residual stresses
role which resulted from irradiation in the variation of studied properties on the
other. Results showed that pack cementation coating layer has roughness, Micro
hardness and wear resistance higher than thermal spray coating layer. Irradiation
results was showed an improvement in studied properties, this was attributed to the
fusing, thermal residual stresses and laser rays role in refining the grains which are
in conjunction with finer microstructure . After irradiation a formation of a hard
phase (martensite) was recorded, this was attributed to the sufficient percentage of
carbon (0.4%) in the selected alloy, this was enshured by microstructure images
taken by optical microscopy. X-ray diffraction showed, for laser surface irradiated
coating layers, presence of the phase due to interaction between the base metal
constituents. A modification of coating phases composition could be concluded for
both coating techniques. Also the two techniques illustrate a formation of coating
layer with a different thickness.