MODELING OF THE CORROSION BEHAVIOUR OF Ti-8Ni-Cr-SYSTEM ALLOYS

For modeling of the corrosion behaviour of Ti-8Ni-Cr system alloys there were used the statistical methods of regression analysis: fractional factor experiment 2^4-1, the Box-Wilson design and the second-order composite-rotatable design. The effect of chromium content in the alloy, the pH values, the experiment duration and the temperature of thermal treatment were studied. An adequate linear model of corrosion rate y=0.1178+0.0636x₁-0.081x₂, where only two factors are significant - the chromium content and the temperature of thermal treatment, were obtained. After the optimization of the adequate regression equation of second order, a canonical analysis of the response surface of optimum was performed. By comparison of the obtained mathematical model with the hardness and the microstructure of alloys, the optimal composition of the alloy was established. (author)