TIN COATINGS GENERATED WITH A PULSED PLASMA-ARC

A systematic study of TiN coatings produced with a low-energy pulsed p lasma are (500 A peak current, 35 ms half-amplitude-full-width duratio n) is presented. The N-2 background pressure was varied in the range 0 .6-10 mbar. Several diagnostic techniques were employed to study the c oatings: Scotch tape test, weighting, scanning electron microscopy (SE M), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), a nd Vickers microhardness. ?he results show that two different microstr uctures of the coatings can be obtained by changing the operating pres sure value: a low-pressure regime where ?he coating presents high poro sity, with agglomerates of diameter in the range 10-60 mu m; and a hig h-pressure regime, for which the coatings are more uniform and dense, with agglomerates of less than 3 mu m size.