(中南大學(xué) 材料科學(xué)與工程學(xué)院， 長沙 410083)
摘 要: 采用硬度測試、 掃描電鏡與透射電鏡研究時效前冷軋預(yù)變形量對2519鋁合金晶界無沉淀帶(PFZ)及第二相大小、 分布和抗晶間腐蝕性能的影響。 結(jié)果表明： 經(jīng)冷軋預(yù)變形后， 晶間析出相細(xì)化并彌散分布， 導(dǎo)致各變形量樣品的時效硬度均提高， 同時使合金到達(dá)峰值的時效時間縮短； 且隨著預(yù)變形量的增加， 合金晶間腐蝕性能由4級降至0級， 抗晶間腐蝕能力增強。 這是由于晶界無沉淀帶變窄， 同時在晶界析出的平衡相由鏈條狀分布逐漸變?yōu)椴贿B續(xù)分布， 使連續(xù)網(wǎng)狀的腐蝕通道轉(zhuǎn)變?yōu)閿嗬m(xù)的腐蝕點， 進而提高了2519合金的抗晶間腐蝕性能。
關(guān)鍵字: 預(yù)變形量; 晶間腐蝕; 2519鋁合金
（School of Materials Science and Engineering, Central South University,
Changsha 410083, China）
Abstract: By hardness tests, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the influence of predeformation reduction before aging on the size and distribution of precipitate phases and inter-granular corrosion resistance of 2519 alloy was determined. The results show that the precipitate in grains is fined after predeformation reduction. The peak-age hardness of samples is correspondingly improved, and the time for peak-aged is shortened. With the increase of the predeformation reduction, the rate of intergranular corrosion (IGC) of 2519 aluminum alloys decreases from 4 to 0, and the IGC resistance is improved. Along grain boundaries, the precipitation free zones (PFZ) is narrow and the distribution of those precipitates changes from continuous chains to non-continuous ones. Then, the discrete corrosion pits form instead of continuous pathway, which results in higher IGC resistance.
Key words: degree of predeformation; intergranular corrosion; 2519 aluminum alloys
