Surface Modification of Laser Alloyed UNS G10150 Steel with Al+Sn Powders: Artificial Neural Model Approach

摘要

Laser Surface Alloying [LSA] offers a reliable and clean technique of depositing coatings unto the substrates to impart increased hardness and corrosion resistance. This work is attempted to improve the hardness and corrosion properties of UNS-G10150 steel, by developing highly corrosion resistant materials using binary combinations of Aluminium and Tin metallic reinforcement materials. A 4.4kW continuous wave Rofin Sinar Nd:YAG laser was utilized for the fabrication process. The steel alloyed surfaces were investigated for its hardness and corrosion behaviour at different laser processing conditions. The steel samples were cut to corrosion coupons, and immersed into 0.5 M H_2SO_4, and 1M HCI media at 30~0C using gravimetric and electrochemical techniques. The microstructures of the developed intermetallic coatings and uncoated samples were characterized by optical (OM) and scanning electron microscope (SEM/EDS). Moreover, X-ray diffractometer (XRD) was used to identify the phases present. The addition of alloying elements caused significant improvement in the hardness and corrosion resistance in the alloyed samples compared with the as-received steel. The improved properties were attributed to the formation of new intermetallic phases (Al_3Sn_9, Al_5Sn_6) and fine eutectic microstructures. In addendum, Response Surface Model [RSM] and Artificial Neural Network Model [ANN] were used for the optimization and modelling of the laser parameters since processing parameters played an important role in the quality of alloyed coating produced. Corresponding experimental results show a good qualitative conformity with the numerical model predictions.