Effect of the Surface Technical Procedure on the Compatibility Characters of W-Na

The compatibility of the tungsten with sodium were investigated. The weight loss rate in 600 ℃ sodium containing 30 μg/g oxygen is about 1×10~(-4) mm·a~(-1) and (2×10~(-4)) mm·a~(-1), respectively for the rotary swaging tungsten and polishing tungsten. The weight loss curves and the corrosion products of two kinds of W-specimens in high temperature sodium are difference significantly, and it indicates that the original surface conditions of the tungsten resulted from the surface technical procedures affect significantly the characters and mechanism of W-Na compatibility. The grain grow, the fracture stress and the micro-hardness are decreased significantly for the corroded rotary swaging W-specimen, and are not influenced so much for the polishing W-specimen. The micro-morphology of the fracture surface appears to be the inter-granular brittle before sodium corrosion for the rotary swaging and polishing W-specimens. The brittle morphologies become much more notable, and appear the inter-and trans-granular fracture mode after sodium corrosion at high temperature for both of W-specimens.