界面能调控熔体中纳米颗粒分布铝热合成铁基ODS合金

发布时间：2018-03-02 05:24

  本文关键词： 铁基ODS合金 界面能 液相调幅分解 纳米AlO粒子 NiAl相　出处：《金属学报》2017年08期 　论文类型：期刊论文

【摘要】：利用铝热合成工艺结合快速凝固技术制备了铁基氧化物弥散强化(ODS)合金。经过优化铝热剂成分,合金熔体中不仅原位生成了a-Al_2O_3纳米颗粒,还发生了液相调幅分解,形成了富Fe、Cr与富Ni、Al的两相结构。因为a-Al_2O_3与富Ni、Al相之间的界面能较低,Al_2O_3纳米颗粒与富Ni、Al相结合,从而在基体中均匀分布。分析了反应熔体发生液相调幅分解的热力学可能性以及纳米颗粒在界面能和Brownian运动影响下的移动速率。实验结果表明,液相调幅分解得到的NiAl相呈球形,直径约50 nm,体积分数约50%;反应合成的aAl_2O_3颗粒直径约5 nm,受界面能作用全部与NiAl相结合。计算表明,受界面能和Brownian运动影响,a-Al_2O_3颗粒移动速率极快,快速冷却过程中完全有时间在两相液体间完成移动和分布。测试表明,铁基ODS合金平均拉伸强度为602 MPa,延伸率为21%,大气环境中1000℃下氧化100 h后增重0.4 mg/cm2。
[Abstract]:The Fe-based oxide dispersion strengthening (ODS) alloy was prepared by using aluminothermic synthesis process and rapid solidification technology. By optimizing the composition of aluminothermic agent, not only a-Al _ 2O _ 3 nanocrystalline particles were formed in the melt, but also the liquid phase amplitude modulation decomposition took place. Because the interface between a-Al2O3 and Nia-rich Al phase can be lower than that of Al2O3 / Al2O3 and Nia-Al2O3 / Al2O3. The thermodynamic possibility of the liquid phase amplitude modulation decomposition of the reactive melt and the moving rate of the nanoparticles under the influence of interface energy and Brownian motion were analyzed. The NiAl phase is spherical, about 50 nm in diameter and 50 nm in volume fraction, and the synthesized aAl_2O_3 particle is about 5 nm in diameter, all of which are combined with NiAl by interfacial energy. Under the influence of interface energy and Brownian motion, the moving rate of Al2O3 particles is very fast. During the rapid cooling process, there is time to complete the movement and distribution between the two phase liquids. The average tensile strength of Fe-base ODS alloy is 602 MPa, the elongation is 21. The weight of Fe-based ODS alloy is increased by 0.4 mg / cm ~ 2 after oxidation at 1000 鈩，

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