ارايه رابطه رياضي چقرمگي شكست پوشش هاي نيكل-فسفر تابع ضخامت بر اساس داده هاي آزمايشگاهي

The mathematical relation for fracture toughness of Ni-P coatings versus thickness on the base of experimental data

In this paper, a mathematical relation is presented to determine fracture toughness of Ni-P coatings related to its thickness on the basis of experimental data. For this purpose, Ni-P coatings with various thickness were deposited on the steel substrate and then heat treated for 1 hr in 400 °C. Fracture toughness of the coatings was estimated 1-3 MPaVm by Vickers indentation method. It was found that thick coatings have lower Kc compared to thin ones. Fracture toughness relations (models) were analysed as different functions. Mean square relative error (MSRE) was calculated for final (models). The results showed less MSRE as well as good agreement between model I (K^^t2)) and the experimental data.