Effect of oxygen flow rate on the deposition rate of α-Al2O3 coatings by anodic evaporation of Al in an arc discharge

N V Gavrilov,A V Chukin,A S Kamenetskikh,A I Men’Shakov,P V Tretnikov

doi:10.1088/1742-6596/1281/1/012019

Abstract

Effect of O2 flow rate on the kinetics of growth and properties of α-Al2O3 coatings deposited by reactive anodic Al evaporation at 640 °C has been studied. It has been shown that the growth rate of coatings changes non-monotonously with O2 flow, rise of the growth rate is due to the increase in the concentration of atomic oxygen in plasma, and the decrease at large O2 flows is associated with transition from the mode of free transit of Al atoms to the diffusion mode.

Highlights

The low-temperature crystallization of Al2O3 coatings and the formation of the high-temperature α-phase is accomplished using intense ion assistance [1]
It has been shown that the growth rate of coatings changes non-monotonously with O2 flow, rise of the growth rate is due to the increase in the concentration of atomic oxygen in plasma, and the decrease at large O2 flows is associated with transition from the mode of free transit of Al atoms to the diffusion mode
Synthesis of coatings by anodic evaporation of Al in an arc discharge in the Ar-O2 medium deposited on the crystallographic template under conditions of a dense ion flow with low (50 eV) energy of ions is characterized by the existence of the maximum of the dependency of the α-Al2O3 deposition rate on the O2 flow rate

Summary

Introduction

The low-temperature crystallization of Al2O3 coatings and the formation of the high-temperature α-phase is accomplished using intense ion assistance [1]. In the cathodic arc discharge with filtered plasma, an increase in O2 pressure up to 0.01 Pa was used for the energy relaxation of Al+ ions and the reduction of their energy in plasma down to ~ 1.4 eV. This allowed performing the deposition of coatings with the energy of ions (40–200 eV) controlled by the bias voltage change and obtaining single-phase α-Al2O3 coatings at 700 °C [4]. The influence of O2 pressure on the properties of α-Al2O3 coatings obtained through PVD methods at low temperatures is scarcely investigated, since these works emphasized such key factor as ion energy

Results

Discussion

Conclusion