MICROHARDNESS IMPROVEMENT BY USING THERMAL SPRAYED NI AND AL COATINGS BY DETONATION GUN

Authors

  • Mukesh kumar Mechanical Engineering, Quantum University, Roorkee, India
  • Mohd Vaseem Mechanical Engineering, Quantum University, Roorkee, India
  • Rajesh Kumar Enginear, Welding/NDT, Engineeres India Limited RRFCL, Telagana, India

Keywords:

Detonation Gun Spray, Erosive wear, Al2O3-TiO2 coating, Ni-Cr coating, Nitriding, Compaction, Microstructural characterization, Microhardness, Surface roughness

Abstract

The present work was undertaken to increase the hardness of aluminium and nickel based coatings deposited
by Detonation spray technique. The experimental work included deposition of Al2O3-TiO2 and Ni-Cr overlays of around
400 micron coating thickness, so as to achieve appropriate adhesion strength and hardness by using detonation gun
spray technique (DS).
Characterization of samples was made for further studies viz. as sprayed condition & post coating treatment. One of the
hardfaced samples was subjected to post spray treatments of nitriding and compaction heat-treatment at 565° C for 2.5
hours and allowed to furnace cool, while another set of samples of both types of coatings was subjected to compaction at
12kN for 15 minutes. Systematic microstructural characterization of the coatings in the as-sprayed, nitrided conditions
were carried out which included microhardness techniques in order to understand the effect of post treatment on the
microstructure of these coatings.
It is found that the microhardness values of base metal are enhanced almost three times after hardfacing/coatings with
the Al2O3-TiO2 & Ni-Cr, using DS, which further enhanced after post treatment of nitriding and compaction. In the case
of nitrided and compacted samples, nickel based coatings showed 33% greater erosion resistance over aluminium based
coatings. Thus post spray treatment of nitriding and compaction could result in higher hardness under given set of
conditions.

Published

2018-04-25

How to Cite

Mukesh kumar, Mohd Vaseem, & Rajesh Kumar. (2018). MICROHARDNESS IMPROVEMENT BY USING THERMAL SPRAYED NI AND AL COATINGS BY DETONATION GUN. International Journal of Advance Engineering and Research Development (IJAERD), 5(4), 498–504. Retrieved from https://www.ijaerd.org/index.php/IJAERD/article/view/3084

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