INVESTIGATION OF PLASMA NITRIDED AlZnMgCu 1.5 ALLOY

摘要

Aluminium alloy (AlZnMgCu 1.5) was nitrided in a modified plasma nitriding unit. Applying suitable experimental conditions, a thin layer of shiny black aluminium nitride (A1N) with hexagonal crystal structure as well as high hardness was formed on the surfaces of the substrates. Due to the volume expansion of A1N layer during nitriding as well as the difference of the thermal expansion coefficients between the A1N layer and the aluminium substrate, distortions and micro-cracks in the A1N layers occurred, which could be observed metallographically. Therefore, the thickness of well adhesive A1N layers formed on the AlZnMgCu 1.5 substrate must be confined below about three micrometers by a proper adjustment of the nitriding parameters.