چكيده به لاتين
Abstract:
Laser engraving is an approach for the material removal from the surface into a specific depth. The laser beam penetrates the surface and removes material in the laser path through melting displacement, ablation and evaporation. Physical simulation of laser engraving leads to a deep understanding of the physics of process. Design of experiments approach describes the output variable of the studied process through the minimum of available expriments.
Response surface methodology is one of the design of experiments approaches, applied for the modeling and analyzing of problems in which a qualitative charactereristic is affected by a number of factors. Also, artificial neural network is a powerfull approach for creating relationship between massive and complicated information, cassed by a number of factors and output of experiment.
In this research, the laser engraving process is considered as a heat transfer problem and simulated physically. In the experimental part of research, a certain number of expriments are designed through design of expriments approach. Then, the laser engraving process is applied for Al- SiC composite sampeles, which are produced through accumulative roll bonding process, using Q-switched Nd: YAG laser.
The qualitative characteristics of engraved zone (width, depth and contrast of engraved zone) are measured. The factors, including assistant gas flow, distance of sample frome beam focus location, pulse repetition frequency, and pumping current considered as effective factors on width, depth, and contrast of engraved zone.
The relationships between factors and each of the qualitative characteristics will be modelled through response surface methodology, and the effect of factors on each of qualitative charecteristics will be tested through analysis of variance.Then, the main effects and the interaction effects of factors will be displayed. The optimal setting of factors, producing qualitative characteristics on target values (minimum width, maximum depth, and maximum contrast) will be determined, and the artificial neural network will be used for estimaing the qualitative characteristics of laser engraving process. Finally, the results of response surface methodology and artificial neural networks approach will be compared with experimental values of output.
Keywords: laser engraving, Al- SiC composite, Design of experiments, Analysis of variance, artificial neural networks
