Influence of nitriding on damping properties of some metallic materials

We study the influence of the ion nitriding process technological parameters, specifically the temperature and composition of the nitrogen — argon saturating medium and the process pressure and duration, on the damping (logarithmic vibration decrement) characteristics of steel 45 and titanium alloy BT1-0 specimens subjected to bending vibrations. The experiment planning method with the use of a Hartley second-order plan is adopted. It is found that nitriding in a hydrogen-free saturating medium increases the level of the damping properties of steel 45 by up to six times and of the alloy BT1-0 by up to 1.5 times. We obtain on the basis of the experimental data regression equations that make it possible to establish the extremal experimental relationships (including those for the steel 45 specimens) between the vibration decrement and the nitriding process technological parameters, thanks to which these parameters can be optimized to achieve the highest values of the vibration decrement.