2A12硬质铝合金表面纳米化机理研究
Study on Mechanism of Surface Nano-crystallization for 2A12 Hard Al Alloy
李 楠1, 郑连泽2
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作者单位：(1. 中船重工集团 第十二研究所, 陕西 兴平 713102; 2. 海军驻汉中地区军事代表室, 陕西 汉中 710032)
中文关键字：2A12硬质铝合金； 表面纳米化； 超音速微粒轰击
英文关键字：2A12 hard Al alloy; surface nano-crystallization; supersonic fine particles bombarding (SFPB)
中文摘要：对2A12硬质铝合金表面进行超音速微粒轰击处理，在材料表层获得纳米晶组织。利用X射线衍射、光学电镜、透射电镜和显微硬度测试技术对试样的微观结构和性能进行测试分析，并对表面纳米化的形成机理及其性能作了初步探讨。结果表明：在强度0.15 A、压强0.3 MPa和时间60 min条件下对2A12铝合金进行超音速微粒轰击为优化工艺，最小平均晶粒尺寸为56 nm，随处理时间的延长，晶粒尺寸缓慢减小并逐渐趋于稳定；随距表面距离的增加，晶粒逐渐由随机取向的等轴状纳米晶变成具有择优取向的不规则形状的亚微米晶，晶粒细化程度逐渐变得不均匀。
英文摘要：The nano-structured surface layer on 2A12 hard Al alloy surface was obtained by SFPB. The microstructure and properties were measured and analyzed by XRD, OM, TEM and microhardness testing. The nano-crystallization mechanism and the property of the surface layer were discussed. The results show that, under the strength of 0.15 A, the pressure of 0.3 MPa, the time of duration of 2A12 alloy 60 min, the average grain size of nano-structured regime is about 56 nm. With the increase of treating time, the grain size reduces slowly, until basically the same with coarse grain matrix. With the increase of the distance from the top surface, the grain turns from nano-meter isometric crystal with random orientation to the submicron crystal with anomalous shape, the grain refining becomes gradually non-uniform.