The Reaearch Of Zirconium Alloy Amorphous Thin Film Performance Used In Nuclear

As a cladding material to protect the nuclear reactors, zirconium alloy need to withstand strong oxidizing erosion caused by high temperature and pressure inside and outside the nuclear reactors. It has been a focus of research to improve the oxidation resistance of zirconium alloys in high temperature and high pressure environment.In this work, a novel method was used to prepare the Zr-Si films: High Target Utilisation Sputtering(Hi TUS). Zr-Si mixed targets were installed with Zr target and Si purity of 99.999%(5N). When the composition of the mixed target was 30 at.%Si, the Zr-Si films with the best glass forming ability were obtained. The conclusions are following:1. It has been found that the designed composition was 30 at.%Si but the actual composition was 25.34 at.%Si from the EDS of samples.2. The field emission scanning electron microscope(FESEM) was used to observe the surface morphology of films. The films prepared by Hi TUS system were uniform, continuous, and no obvious defects. Because of the roughness of the substrates, the amorphous films on glass were more uniform and continuous than on Zr substrate.3. The nanoindentation instrument was used to test the mechanical properties of films. It has been found that the mechanical properties of the β-Fe Si2 films were superior and the Zr-Si films with the best glass forming ability had stronger binding force with the substrates.In this work, high temperature and high pressure reactor was used to simulation the environment inside and outside the nuclear reactors. We design different parameters to study the anti-oxidation corrosion and phase structure of Zr-Si amorphous films. The conclusions are following:1. The field emission scanning electron microscope(FESEM) was used to observe the section morphology of oxide films. It has been found that the oxide layerof zirconium alloy with Zr-Si amorphous film was thinner than the sample without Zr-Si amorphous film in the same oxidation time and oxygen content. Addition, the oxide layer of samples in 1.0%H2O2 solution was thinner than the samples in 3.0%H2O2 solution.2. It is unusual that the oxide layer of samples which oxidized corrosion about 150 h was thinner. This can be attributed to the oxide layer off.3. It has been proved that the oxide layer of zirconium alloy with Zr-Si amorphous film was uniform and continuous, but the oxide layer of zirconium alloy without Zr-Si amorphous film cracked and fell off.4. X-ray diffraction was used to characterize the structure of the oxide. It has been found that a lot of tetragonal zirconia appeared in the samples with Zr-Si amorphous film to protect zirconium alloy from oxidation. With prolonged oxidation, tetragonal zirconia changed to monoclinic phase zirconia.