High power diode laser surface hardening of AISI 4130; statistical modelling and optimization

Mahmoud Moradi, Mojtaba KaramiMoghadam

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)
1 Downloads (Pure)


Laser surface hardening of AISI 4130 carbon steel was conducted with a high power diode laser using Response Surface Methodology. Scanning speed, laser power and focal plane position were considered as the input process variables and cross sectional geometry of the hardened area, average micro-hardness and the ferrite phase percentage were considered as process responses. The effect of parameters on the responses variations were investigated using analysis of variance. Microstructure evaluation of the laser hardened zone was performed using optical and field emission scanning electron microscopy. Results indicated that by increasing the laser power and decreasing the scanning speed and focal plane position, higher surface hardness with more penetration in depth, higher average micro-hardness and minimum ferrite percentage will be achieved. Finally, the process was optimized by desire ability approach based on the applied statistical analyses. Minimum value of percentage of the ferrite and maximum value of the other responses are considered as optimization criteria. The recommended optimized results were validated using the experimental tests. The results show that the hardness of the diode laser hardening process is 3 times of the hardness of the base metal. Laser-overlapping scanning is performed in the optimum setting and effect of overlapping percentage is investigated.
Original languageEnglish
Pages (from-to)554-570
Number of pages17
JournalOptics and Laser Technology
Early online date29 Oct 2018
Publication statusPublished - 1 Apr 2019
Externally publishedYes

Bibliographical note

NOTICE: this is the author’s version of a work that was accepted for publication in Optics and Laser Technology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Optics and Laser Technology, 111, (2019) DOI: 10.1016/j.optlastec.2018.10.043

© 2019, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/


  • Design of experiments
  • High power diode laser
  • Laser surface hardening
  • Optimization
  • Overlapping

Fingerprint Dive into the research topics of 'High power diode laser surface hardening of AISI 4130; statistical modelling and optimization'. Together they form a unique fingerprint.

Cite this