Relation of hardness and oxygen flow of Al2O3 coatings deposited by reactive bipolar pulsed magnetron sputtering

High Rate Deposition of Al2O3 Coatings Reactively Sputter Deposited

“…Figure 3 presents the evolution of the friction coefficient recorded during 2 mm bidirectional multipass tests performed on a Cr/CrO x /Al 2 O 3 coating (2.3 µm thick) under different applied normal loads of 2, 5 and 10 N. The picture in Figure 3 presents the end of a scratch test performed under a continuous progressive load applied to a diamond tip with a radius of 200 µm. It clearly shows that no delamination of the coating or cracks are observed up to a normal applied load of 90 N, in agreements with the result reported by Bobzin et al6 According to other studies,15,16 concerning the synthesis of mechanical coatings deposited by means of magnetron sputtering, the criterion for a good adhesion of the film is defined as the appearance of the first crack during the scratch at normal applied loads between 46 and 60 N, confirming the excellent adhesion of our alumina coatings to WC samples.…”

“…On the other hand, it is known that the crystallinity and the properties of alumina coatings deposited by plasma processes depend on the plasma ion density, the oxygen flow rate, the substrate temperature and the ion bombardment of the growing film. Then, RF sputtering, Pulsed DC sputtering and the recently inverted cylindrical magnetron system are commonly used to deposit crystalline ( γ and α ) coatings in the temperature range of 300–550 °C 6–8. The positive influence of CrO x underlayers on the growth of α ‐Al 2 O 3 has also been reported 2.…”

Structure and Space Charge Inhibition Performance of Reactive RF Magnetron Sputter Deposited Al2O3 Thin Film on the Fiber Surface

“…In this study, considering the Al 2 O 3 is a well-known insulator which has good mechanical, thermal, and chemical stability [9,12], and being frequently used as a coating material [13,14] and nano-fillers of insulation paper. The Al 2 O 3 function thin film was deposited on cellulose insulation pressboard by using reactive RF magnetron sputtering under room temperature.…”

Oxidation behaviour of TiAlYN/CrN and CrAlYN/CrN nanoscale multilayer coatings with Al2O3topcoat deposited on γ-TiAl alloys

“…Therefore, Al 2 O 3 thin films are widely used as wear-resistant coatings, particularly on high-speed metal cutting tools. They are mainly produced by chemical vapour deposition [28,30,32], which is an economical coating technique, but physical vapour deposition also have been applied because crystalline alumina coatings can be deposited at lower temperatures with high compressive stresses, less intrinsic defects and free of chlorides [29,31,33]. The thin films were predominantly metastable kand g-alumina which transformed to stable a-Al 2 O 3 at temperatures of about 1000 C [34].…”