(中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 利用力學(xué)性能測(cè)試、金相、X射線衍射、掃描電鏡與透射電鏡等研究微量Nd對(duì)2519鋁合金組織與力學(xué)性能的影響。結(jié)果表明：添加0.14% Nd提高合金的強(qiáng)度，硬度最適宜；Nd元素與Cu和Al 元素主要形成Al8Cu4Nd金屬間化合物，并沿晶界分布。這些金屬間化合物有效地阻礙高溫時(shí)基體的變形和晶界的遷移，從而提高了合金的高溫強(qiáng)度。Nd能細(xì)化合金的時(shí)效強(qiáng)化相，提高合金力學(xué)性能。添加0.14% Nd時(shí)，合金在300 ℃時(shí)的抗拉強(qiáng)度提高15.4%，室溫抗拉強(qiáng)度提高4.4%；當(dāng)Nd含量進(jìn)一步增加時(shí)，合金室溫及高溫力學(xué)性能降低。
關(guān)鍵字: 2519鋁合金；顯微組織；力學(xué)性能；熱穩(wěn)定性；稀土；Nd
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effect of Nd on the mechanical properties and microstructures of 2519 aluminum alloy were investigated by means of hardness test, mechanical properties test, X-ray diffraction, OM, SEM and TEM. The results show that, with addition of Nd, the hardness and strength enhance. Nd can react with Al and Cu, and the intermetallic compound Al8Cu4Nd forms, which disperses along the grain boundaries. The mechanical properties at elevated temperature are improved because this dispersed compound prevents the deformation of matrix and movement of the grain boundaries at elevated temperature. The aging precipitates can be refined with appropriate addition of Nd, which increases the mechanical properties of the alloy. Adding 0.14% Nd increases the tensile strength about 15.4% at 300 ℃ and that at room temperature by 4.4%. With further addition of Nd, the mechanical properties at room and high temperature decrease.
Key words: 2519 aluminum alloy; microstructure; mechanical properties; thermal stability; rear earth; Nd
