Effects of evaluated temperature on tribological behaviors of micro-arc oxidated 2219 aluminum alloy and their field application

The effect of evaluated temperatures on tribological properties of micro-arc oxidated (MAO) 2219 aluminum alloy was investigated. Tribotests were carried out under 25, 80, 120, and 160 °C, and the field drilling test was carried out in “Yang D1 Well”. The results reveal that the friction coefficient of MAO sample decreases with the increase of temperature, the wear rate of MAO sample increases with the increase of temperature, and the load bearing capacity of MAO coating reduces when the temperature goes up. However, comparing with the untreated sample, the wear rate of MAO sample is reduced by 60% at 160 °C. The main wear mechanism of MAO sample is slight abrasive wear under high temperature. The outer loose layer of MAO coating is obviously sheared off under low load and high temperature, resulting in the decrease of friction coefficient. The low loading capacity causes the high wear rate of aluminum alloy at elevated temperature. In the field application, the minimum amount of wear loss is 0.06 mm in the B position of the MAO aluminum alloy drilling pipe.