Studies of technological parameters influencing the nitriding behavior of spray-formed Al alloys

The scope of this report covers both the influence of the duty plasma cycle and the initial surface characteristics, including the specimen shape. Despite equivalent general nitriding conditions (temperature, time, voltage), over time the plasma duty cycle and the target value of plasma duty lead to different thicknesses and coverage of the nitride layer. For a better understanding of the nitriding mechanism, analyses of interrupted nitriding tests were carried out. The results of plasma nitriding have been characterized by examining metallographic cross sections with optical microscopy, surface coverage by scanning electron microscopy (SEM), as well as measuring aluminum nitride layer thickness with different methods. Mechanical properties were studied using microindentation. Adhesion was tested by scratch tests.