Effects Of Low-energy Charged Particles Irradiation And Atomic Oxygen Exposure On Zr-based Alloy

The irradiation tests of160keV proton and120keV nitrogen ion as well as5eVatomic oxygen (AO) exposure test were conducted on Zr702and ZrTiAlV alloy, usinglow-energy charged particle irradiation equipment and atomic oxygen exposureequipment, respectively. The effects of low-energy charged particle irradiation and AOexposure on Zr-based alloy have been studied by means of metallographic microscope,graze small angle X-ray diffraction(GAXRD) and transmission electron microscope(TEM), X-ray photoelectron spectroscopy analyzer(XPS), nano-indentation machine,cryogenic temperature vacuum friction and wear machine and scanning electronmicroscope (SEM).Microstructure analysis results indicated that there was not new phase producedon the surface of Zr702and ZrTiAlV alloy after proton irradiation and atomic oxygenexposure. But ZrN was found on the surface of Zr702, while AlN and TiN were foundon the surface of ZrTiAlV alloy after nitrogen ion irradiation combined with atomicoxygen exposure. After the atomic oxygen exposure, denudation traces were present onthe surface of Zr702and ZrTiAlV alloy, and the roughness was found to reduce. Thesurface roughness of Zr702and ZrTiAlV alloy increased obviously after chargedparticles irradiation combined with atomic oxygen exposure.Nano-indentation test results indicated that nano-hardness of Zr702and ZrTiAlValloy increased obviously after charged particle irradiation, and decreased obviouslyafter atomic oxygen exposure. The combined effects of charged particle irradiation andAO exposure on nano-hardness come from the single effect, respectively. Due togeneration of nitrides on surface induced by nitrogen ion irradiation, the nano-hardnessof Zr702and ZrTiAlV alloy was found to increase after nitrogen ion irradiation andatomic oxygen exposure.The friction test results indicated that the initial friction coefficient of Zr702sample in air at room temperature of the charged particle irradiation and atomic oxygenexposure was less than that of the charged particle irradiation or atomic oxygenexposure sample, with the data of0.3compared with0.45. As in vacuum at cryogenictemperature, the friction coefficient of charged particle irradiation and atomic oxygenexposure Zr702sample increased firstly and then decreased obviously at the initialstage of friction and wear test. The influence of charged particle irradiation and atomic oxygen exposure on friction coefficient of ZrTiAlV alloy was found to be lessremarkable due to inherent higher hardness of the ZrTiAlV alloy. The frictioncoefficient of ZrTiAlV alloy remained around0.4in vacuum at cryogenic temperatureeven after charged particle irradiation or atomic oxygen exposure.The wear test and morphology observation indicated that wear mechanism ofZr702and ZrTiAlV alloy was not varied after charged particle irradiation and atomicoxygen exposure erosion, but the wear resistance of ZrTiAlV alloy either in air at roomtemperature or in vacuum at cryogenic temperature was enhanced after chargedparticle irradiation while reduced after atomic oxygen exposure erosion. It was foundthat the weakening effect of atomic oxygen exposure was greater than the enhancedeffect of proton irradiation but less than the enhanced effect of nitrogen ion irradiation.