THE MICROSTRUCTURAL AND THICKNESS UNIFORMITY OF ZIRCONIA COATINGS PRODUCED BY RF ION PLATING

An ion plating system, which utilizes r.f. substrate biasing, was stud ied to determine the influence of source to substrate distance on the microstructure and thickness uniformity of zirconia coatings. Coating thickness measurements were used to evaluate parameters from equations which describe uniformity in absolute and relative terms with distanc e from the vapour source. The results show that microstructure and thi ckness uniformity are significantly influenced by the ratio of the pla sma bombardment intensity and coating material arrival rate; energetic bombardment effects from the plasma become relatively more prominent on substrate surfaces positioned remotely from the source.