摘要
采用喷射沉积工艺制备了SiCP/Al-8.5Fe-1.3V-1.7Si复合材料,并通过热压后多道次热轧制备了板材。研究了板材在不同温度下热暴露过程中第二相粒子、SiC/Al界面和位错密度的变化,并通过X射线衍射分析了板材在热暴露过程中的物相变化。结果表明,复合材料经热加工后第二相粒子保持弥散细小,为50～80nm,SiC/Al界面干净,没有脆性相生成;在500℃暴露200h后,第二相粒子几乎没有变化;在550℃暴露200h后,第二相粒子略有长大,没有明显的脆性相生成;600℃下暴露10h后,SiC/Al界面处生成Al4C3相,第二相粒子长大至400～500nm,并生成Al13Fe4相;在550℃热暴露过程中,随着暴露时间变长,位错密度增加。SiC颗粒分解向基体中析出游离态Si,抑制了Al12(Fe,V)3Si的粗化和分解,提高了复合材料的耐热性能,因此该复合材料在550℃以下具有良好的热稳定性能,550℃以上耐热性能急剧下降,热暴露过程中位错增殖。
SiCp/Al-8.5Fe-1.3V-1.7Si composite prepared by spray deposition was densified by hot pressing, and then was rolled into the sheets. Evolution of second-phase dispersions, SiC/Al interface and dislocation density of the composite sheet during hot exposure were investigated, and phase transformation during hot exposure were analyzed by X-Ray Diffraction. The results showed that the dis- persions kept fine without brittle phase formation and the SiC/Al interface kept clean. The second-phase grew hardly during the expo- sure at 500℃ for 200h. This phase grew slightly without obvious brittle phase formation during the exposure at 550℃ for 200h, while the phase coarsened rapidly when exposure temperature was above 550℃. A14C3 phase formed near the SiC/A1 interface, and dispersions grew to 400 - 500nm with Al13Fe4 phase formation after the exposing at 600℃ for 10 hours. Dislocation density increased along with the increase of exposure time at 550℃. Decomposition of SiC particles results in elevated Si concentration, and restrains Al12 （Fe, V） 3 Si from coarsening and transforming into Al13 Fe4. The composite is characterzied with good thermal stability when exposed below 550℃ , heat resistance of the composite worsens when exposed above 550℃ , dislocation is propogated during the exposure at 550℃.
出处
《航空材料学报》
EI
CAS
CSCD
北大核心
2012年第5期54-59,共6页
Journal of Aeronautical Materials
基金
国家自然科学基金(51004050)
淮海工学院人才引进科研启动基金(KQ09028)
关键词
喷射沉积
耐热铝合金
复合材料
热暴露
显微组织
spray deposition
heat resistant alloy
composite
hot exposure
microstructure
