| 摘要: |
| 为提高铝合金材料力学性能,采用超音速微粒轰击(SFPB)技术对2A14铝合金进行表面纳米化处理,利用XRD、SEM和TEM等研究2A14铝合金表层第二相颗粒的弥散分布和形貌变化机理。结果表明:材料表面经强烈塑性变形形成约30 μm厚的纳米层和约120 μm厚的过渡层,表面纳米层晶粒尺寸为50~100 nm,表面显微硬度提高了1倍多,纳米层和过渡层中第二相颗粒得到细化,总体弥散分布比基体更加均匀,距表面距离越近,细化效果和总体弥散分布越好;在过渡层里部分第二相颗粒被亚晶界切分,在纳米层中第二相颗粒均被纳米晶包裹,第二相颗粒的边界与纳米晶晶界部分重合。第二相颗粒被纳米晶包裹影响纳米层晶界迁移机制,对材料表面性能的改善有积极意义。 |
| 关键词: 表面纳米化 铝合金 第二相颗粒 超音速微粒轰击 |
| DOI：10.11933/j.issn.1007-9289.2016.03.015 |
| 分类号: |
| 基金项目:国家自然科学基金(51275517) |
|
| Influence of Surface Nanocrystallization on the Second Phase Particles of 2A14 Aluminum Alloy |
|
YANG Jian-hai1, ZHANG Yu-xiang1, GE Li-ling2, ZHANG Xin1, CHEN Jia-zhao1
|
|
1.Department of Power Engineering, Rocket Force University of Engineering, Xi'an 710025;2.School of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048
|
| Abstract: |
| By means of supersonic fine particles bombarding (SFPB), a nanostructured surface layer was formed on 2A14 aluminum alloy plate to improve the mechanical properties. The dispersive distribution and morphology change mechanism of the second phase particles (SPPs) of the surface microstructure were systematically characterized by using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The micro-hardness was measured along the depth of the treated sample using micro-hardness instrument. Results show that the nanostructured layer with a thickness of 30 μm and refined structure layer with a thickness of 120 μm are induced by severe plastic deformation on the material surface. The grain size of the surface is 50-100 μm. The surface micro-hardness increases more than 1 time. SPPs of the nanostructured layer and transition layer are refined, and the general dispersion distribution is more even than the base material. The SPPs's refinement effect and general dispersion distribution effect are better when SPPs from the surface are closer. SPPs are partly segmented by grain subboundary in the transition layer. SPPs are wrapped by nanocrystalline in the nanostructured layer. The grain boundary migration mechanism is affected when the boundary of SPPs and nanocrystalline grain boundary partly overlap. This has a positive significance on the improvement of the material surface properties. |
| Key words: surface nanocrystallization aluminum alloy the second phase particles (SPPs) supersonic fine particles bombarding (SFPB) |
