The development of a deposition system based on closed field unbalanced magnetron sputter ion plating (uniform deposition and plasma), has greatly increased the number of complex nitrides that it is possible to routinely deposit. The new alloy nitrides can increase the hardness of standard TiN by a factor of 2, and can consequently result in longer tool life, In order to maintain high levels of coating to substrate adhesion, it is necessary to gradually grade the composition of the film in the interface region. Grading of an alloy nitride such as TiZrN will ensure minimum L(c) scratch adhesion levels of 75 N. The technique can be closely controlled and is very flexible, enabling the changes in composition to be attained with precision.

The gradual reduction in the use of electroplated cadmium as a corrosion barrier for aircraft parts has led to the development of ion- vapour-deposited (IVD) aluminium as an alternative. The most common IVD technique is the McDonnell Douglas “Ivadize” process, but the morphology of such aluminium coatings is usually open and columnar. Consequently, a post-deposition shot peen is used to densify the structure. This has led to very poor control over the thickness and uniformity of the coating, and precision parts cannot be coated by such techniques. The use of multimagnetron ion plating can guarantee close control over the coating dimensions by the precise deposition of fully dense aluminium films which do not require peening. To further improve the properties of the films, a series of aluminium alloys have been deposited to provide enhancement of the corrosion and tribological properties of the films.

Graded DLC based coatings and multilayers for wear resistance applications have been produced using a novel hybrid unbalanced magnetron sputtering/ low pressure CVD system. The main features of this highly flexible and scalable process are discussed. These films have been characterised using a variety of techniques including SEM, microhardness, adhesion, wear rate and lifetime tests. For example: microhardness of > 4000 Hv; excellent adhesion, Lc 115-125 N; coefficient of friction during prolonged running against WC of 0.15; volumetric wear rates 1/5 of that of TiN. The process is ideally suited to large substrate size and volume production for many different kinds of applications.