Influence of process control on nitride layer formation of spray-formed Al alloys during plasma nitriding

摘要

Process control of the plasma glow seam forming around the material surface during plasma nitriding can be carried out by adjusting the plasma duty cycle. The interactions between the plasma and the material surface can be directly influenced and optimised with respect to the nitride layer formation. Plasma nitriding of different spray-formed Al alloys is investigated by varying the plasma duty cycle and nitriding time. By means of adaptive process control, compact nitride layers are generated that exhibit thicknesses of about 4 μm, leading to an increase in hardness from 2 GPa up to 12 GPa. The wear resistance of spray-formed Al alloys is enhanced up to two orders of magnitude.