(江蘇大學 材料科學與工程學院，鎮(zhèn)江 212013)
摘 要: 將鋁青銅試樣分別置于0.3%、3%和6%(質量分數(shù))的NaCl溶液中腐蝕72 h，然后利用超聲空蝕裝置對腐蝕后的鋁青銅試樣進行超聲空蝕實驗。借助金相顯微鏡、掃描電子顯微鏡和激光共聚焦顯微鏡觀察試樣的表面形貌，測量試樣的表面粗糙度、累積質量損失、自腐蝕電位和自腐蝕電流密度。結果表明：試樣在6%NaCl溶液中腐蝕后，其表面出現(xiàn)明顯的材料剝落現(xiàn)象。在空蝕60 min條件下，試樣的表面粗糙度和累積質量損失隨著NaCl溶液質量分數(shù)增加呈總體上升趨勢。自腐蝕電流密度證明空蝕后的試樣的耐腐蝕性更強。經(jīng)6%NaCl溶液腐蝕的試樣在空蝕后期的空蝕速率有下降趨勢。隨著NaCl溶液質量分數(shù)的增加，被腐蝕試樣的空蝕加劇；當NaCl溶液質量分數(shù)達到6%時，由于Cu2O氧化膜的存在，材料的去除速率降低，材料的累積質量損失率與溶液的質量分數(shù)之間不存在正相關關系。累積質量損失隨著空蝕時間的延長不斷增加；同時，試樣表面出現(xiàn)硬化層，截面硬度沿深度方向逐漸下降。
關鍵字: 超聲空蝕；腐蝕；NaCl溶液；質量分數(shù)；質量損失；表面形貌
（School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China）
Abstract:The aluminum bronze samples were corroded by 0.3%, 3% and 6% NaCl solution for 72 h, and then the ultrasonic cavitation experiments were carried out on corroded aluminum bronze samples using ultrasonic cavitation device. The surface morphology of the samples was observed by means of metallographic microscope, scanning electron microscope and confocal laser microscope. The surface roughness, accumulated mass loss, self-corrosion potential and self-corrosion current density of the samples were measured. The results show that after corrosion in 6%NaCl solution, the surface of the sample has obvious material-peeling phenomenon. After cavitation erosion for 60 min, the surface roughness and accumulated mass loss of the samples increase with the increase of NaCl solution mass fraction. The corrosion current density proves that the corrosion resistance of the sample after cavitation erosion is stronger. For the samples corroded by 6%NaCl solution, the cavitation erosion rate tends to decrease in the later stage of cavitation erosion. The cavitation erosion of corroded samples is intensified with the increase of NaCl solution mass fraction. When the NaCl solution mass fraction reaches a certain value, the removal rate of the material decreases due to the presence of Cu2O oxide film, and there is no positive correlation between the cumulative mass loss rate of the material and the NaCl solution mass fraction. The accumulated mass loss increases with the prolonging of cavitation impact. Meanwhile, a hardened layer appears on the surface of the sample, and the cross-section hardness decreases gradually along the depth direction.
Key words: ultrasonic cavitation erosion; corrosion; NaCl solution; mass fraction; mass loss; surface morphology
