STUDY OF SURFACE LAYERS ON PURE TITANIUM PRODUCED BY LASER GAS NITRIDING

J. H. Abboud; A. F. Fidel; Y. Benyounis

doi:10.66411/jer.v10i10.176

Authors

J. H. Abboud Dept. of Mech. Eng, Garyounis University, Benghazi, Libya Author
A. F. Fidel Dept. of Mech. Eng., Omar Al-Mukhtar University, Al-Bythaa, Libya Author
Y. Benyounis Dept. of Industrial Eng., Garyounis University, Benghazi, Libya Author

DOI:

https://doi.org/10.66411/jer.v10i10.176

Keywords:

Laser hardening, CP Titanium, Microstructure., XRD

Abstract

Laser gas nitriding process is a widely accepted technique for modifying the surface structure and composition of titanium and titanium alloys without altering the bulk properties. In the present work, laser gas nitriding of commercial purity titanium with continuous wave 3 kW Co2 laser has been investigated experimentally. The aim is to increase the surface hardness and hence improve related properties such as wear and erosion. The processing parameters were as follow: 2.5 kW laser power, 15 mm/s specimen scanning rate, and 17 L/min nitrogen gas flow rate. Single and overlapping layers were produced and pure and diluted nitrogen gas was used. The results indicated that laser surface melting of pure titanium in nitrogen atmosphere produced unevenly distributed TiN of dendritic morphology extended to a depth of ~ 0.5mm. The volume fraction of the TiN dendrites decreased gradually with increasing depth from the surface. As a result of TiN formation, the hardness increased substantially. Diluting the nitrogen gas with argon gas was found to have a beneficial effect in decreasing cracking but decreased the resulting hardness level and the nitrided depth

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