Sputter deposition of crystalline alumina coatings

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

“…Thus, both signal intensity of the aluminum lines measured by OES and the cathode voltage were used as control variables for the reactive sputtering deposition of Al 2 O 3 . The cathode voltage and the intensity of the aluminum lines in the OES spectrum were also used as control variables for the reactive sputtering deposition of Al 2 O 3 by Cremer et al [6] and Schneider et al [7 8].…”

“…It is likely to be caused by the change to the poisoned sputtering mode (see Fig. 8, developing of the cathode voltage and deposition rate in zone 4), which implies the formation of amorphous structures [6].…”

Face-centered cubic (Al1−xCrx)2O3

“…Previously, only one type of solid solution is known; the thermodynamically metastable corundum-structure (Al,Cr) 2 O 3 [1][2][3][4][5][6] of the stable binary oxides, α-Al 2 O 3 (corundum) and α-Cr 2 O 3 (eskolaite), which are well-studied in terms of synthesis and characterization [see, e.g, [7][8][9][10]. The only known cubic phase in the archetypical oxide system of alumina is the defect spinelstructure γ-Al 2 O 3 [11,12].…”

Comparison of (Ti,Al)N and (Ti,Al)N/γ-Al2O3 coatings regarding tribological behavior and machining performance

“…Another successful commercial hard coating is Al 2 O 3 coating deposited by CVD technology, which is produced at temperatures of about 1000°C limiting the choice of substrate. In the last decade, developments on the plasma sources, especially pulse technology, gained increased attention and made it possible to produce γ-Al 2 O 3 coatings on tools with PVD technology in lower temperatures about 550°C [10]. Crystalline PVD γ-Al 2 O 3 coatings exhibit high hot hardness, high chemical inertness, and high thermal stability at elevated temperatures [11][12][13][14].…”