Abstract
Lasers find wide application in surface engineering due to their precision of operation, short processing time, and low cost. Laser surface treatment involves solid heating and phase change at the irradiated surface. Since the process is involved with high temperature and small size of the irradiated spot, experimentation of the heating process is difficult and expensive. The model studies offer physical insight into the heating process, which enables optimization of the processing parameters for high-end product quality. Laser-heated surfaces suffer from high cooling rates because of the high speed of solidification in the irradiated region. This, in turn, results is high temperature gradients and high levels of thermal stresses in the heated region. As the stress levels exceed, the elastic limit of the irradiated substrate material and the treated surface undergoes asperities while limiting the practical application of the treated surface. Consequently, investigation into laser-induced thermal stress and experimentation of the residual stress becomes essential. In the present work, laser heating of steel surface is modeled after considering half and full geometries of the heated substrate. Although half space assumes plane symmetry for the moving work pieces while reducing the computational effort, it predicts lower stress levels as compared to full size consideration. Therefore, both cases are considered and temperature as well as stress fields predicted for both cases are compared. ABAQUS finite element code is introduced to simulate temperature and stress fields. The study is extended to include the experimenting of the steel surfaces in line with the simulations. Morphological and metallurgical changes in the laser-treated layer are examined using the electron scanning microscope and energy dispersive spectroscopy. The residual stress developed at the surface is measured incorporating the X-ray diffraction (XRD) technique. It is found that the residual stress predicted from the numerical simulations agrees well with the XRD data.
Original language | English |
---|---|
Title of host publication | Laser Machining and Surface Treatment |
Publisher | Elsevier Ltd. |
Pages | 25-46 |
Number of pages | 22 |
Volume | 9 |
ISBN (Print) | 9780080965338 |
DOIs | |
State | Published - May 2014 |
Bibliographical note
Funding Information:The authors acknowledge the support of King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia.
Keywords
- Bending
- Laser heating
- Microhardness
- Modeling
- Residual stress
- Steel
- Thermal stress
ASJC Scopus subject areas
- General Materials Science
- General Engineering