Hot Isostatic Processing Of The Uranium Surface Aluminum Coating (titanium) And Interface Characteristics Of The Impact

corrosion-resistant property of uranium enhanced by Al, Ti, Zn, Al-Zn coatings, which prepared by electroplate, chemical plating and physical vapor deposition. uranium maybe lost protection by coating, however, for microcracks exit in coating, the bonding strength between coating and substrate is low. This paper utilized hot isostatic pressing(HIP) that could simultaneously offer high pessure and elevated temperature, microcracks and caves would be closed by plastic deformation, coating's structure would be modified, atoms of coatings and substates interdiffusion each other which made the bonding stronger, corrosion-resistant property of coatings was better.Samples of Al(Ti) coatings on uranium which were prepared by magnetron sputtering, treated by hot isostatic pressing.They were annealed without pressing for comparison.Density of coatings before and after HIPed measured by Archimedes. Bongding surveyed by tensile tests.Phases and morphologies of coating and interfaces were investigated by X-Ray diffraction(XRD) scanning electron microscopy(SEM) and energy dispersive spectrometer(EDS), electrochemical corrosion behaviors of samples were investigated by electrochemical techniques.The results shew that coatings'density were closed to theoretical density, Microcracks and caves vanish. The samples of aluminum coating on uranium were HIPed at 480℃/2h/100MPa,300℃/0.5h/60MPa,250℃/0.5h/60MPa,200℃/0.5h/ 60MPa, separately. The interfaces after HIPed were sinuous, this indicated U and Al atoms interdiffused, which strengthen the bonding. UAl3 and UAl2 formed in the interface at elevated temperature. The details were that UA12 formed at 250℃HIPed, UAl3 was produced above 300℃HIPed, UAl3 was more as temperature higher, whereas UAl2 was less. And UAl2 was detected HIPed at 200℃and quantity of UAl2 was very low. Corrosion-resistant property of aluminum coating HIPed at 200℃was better than that of coating without HIP obvious. That can conclude that post-treatment at low temperature was good for its integrative performance.Anealing at vacuum promoted interdiffusion and reaction between coatings and substrates, whereas, it couldn't vanish defects in coatings.Surface of titanium coatings on uranium compacted by HIP treatment at 600℃/0.5h/100MPa,655℃/0.5h/100MPa, separately. Bongding strenghten between titanium coatings and uranium substates improved to 17MPa from 11MPa. UAl2 layer formed at interface after HIPed, however, UAl2 wasn't observed when the samples post-treated at the same temperature in vacuum. This showed that pressure boosted intermetallic phases grow. Corrosion-resistant property of titanium coating HIPed improved to some extent.At the condition of 200/0.5h/100MPa, the performance of corrosion-resistant was enhanced dramatically for alumium coatings on uranuim.