Influence of Bias Voltages on Microstructures and Residual Stress of Aluminum Coatings on Uranium Substrate

Influence of different bias voltages on microstructures and residual stress of aluminum coatings is investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray stress analyzer, respectively. The result shows that the microstructures are influenced strongly by bias voltages, of which are worst at - 300 V and at low bias voltages are better than at 0 V. The preferential orientation of crystal planes shift from (111) to (200) above -200 V. The residual stress of all coatings is small, which has a change from tensile to compressive stress with the increase of bias voltages.