2024铝合金表面机械多重碾磨微纳米化研究

Surface Micro-nano Crystallization of 2024 Alloy Induced by Machinery Multi-grinding

为提高2024(Al-Cu-Mg系)合金的力学性能,采用表面机械多重碾磨(MMGS)技术对其表面进行2道次的塑性变形。利用显微硬度测试、力学性能测试、透射电镜以及扫描电镜等测试手段,研究了经表面碾磨加工后的商用2024铝合金的显微硬度、力学性能和微观结构变化。结果表明,与T351状态相比,商用2024铝合金表面经过碾磨处理2道次后表层显微硬度(HV)最高可达185,提高了18%;屈服强度可达475 MPa,提高了22%;抗拉强度可达498 MPa,提高了16%;同时保持较高的伸长率。表层的晶粒被细化,平均尺寸约为800nm,表明MMGS方法是2024铝合金表面微纳米处理有效的方法之一。

In order to improve the mechanical properties of 2024（Al-Cu-Mg series）alloy,machinery multi-grinding of the surface（MMGS）processing was applied to form two pass deformation.The microhardness,mechanical properties and microstructure changes in commercial 2024 aluminum alloy after MMGS were investigated by micro-hardness test,mechanical properties test,transmission electron microscopy（TEM）and scanning electron microscopy（SEM）.The results reveal that,compared with the T351 state,micro-hardness and yield strength as well as tensile strength of the surface reach about 185 HV,475 MPa and about 498 MPa,increased by 18%,22% and 16%,respectively.Grains size of the surface is refined to about 800 nm.MMGS processing is one of the effective methods for the 2024 aluminum alloy to obtain the micro-nano crystallization.