纳米SiC颗粒对Mg-9Al合金晶粒组织细化研究  

Study on microstructure refinement of Mg-9Al alloy with nano-SiC particles

作　　者：王殿君 梁英 高恩达 刘崇林 李思远 WANG Dianjun;LIANG Ying;GAO Enda;LIU Chonglin;LI Siyuan(Modern Manufacturing Institute,Heilongjiang Institute of Technology,Jixi 158100,China)

机构地区：[1]黑龙江工业学院现代制造工程学院,黑龙江鸡西158100

出　　处：《材料科学与工艺》2025年第1期82-88,共7页Materials Science and Technology

基　　金：黑龙江省自然科学基金联合引导项目(LH2019E117)。

摘　　要：纳米颗粒对镁合金的微观组织细化及力学性能的提升具有十分重要的意义。本文采用半固态搅拌与高能超声分散的方法成功制备出纳米SiC/Mg-9Al复合材料,利用OM、XRD、SEM、TEM等设备对复合材料进行微观组织表征。结果表明:纳米SiC颗粒能够显著的细化Mg-9Al合金微观组织。当纳米颗粒添加量为1.0vol.%时,复合材料晶粒组织细化最为明显,为(71.9±28)μm,相比于基体合金晶粒尺寸减小了约63%。研究表明,纳米颗粒在镁基体中分散机制主要为沿α-Mg的晶界分布及少量的晶内分布。同时,揭示了晶粒细化机制为位于晶界的纳米颗粒能够快速吸附在生长的α-Mg晶粒表面,有效地抑制了溶质元素的扩散,显著降低了枝晶生长速率,使得熔体的成分过冷度增大,降低了结晶潜热的释放,能够激活更多的异质形核位点,从而提高了镁合金的形核率,得到了显著细化的晶粒组织。Nanoparticles are of great importance for the refinement of microstructure and improvement of the mechanical properties of magnesium alloys.In this paper,nano-SiC/Mg-9Al composites were successfully prepared by semi-solid stirring and high-energy ultrasonic dispersion method,and the microstructure was characterized by OM,XRD,SEM and TEM.The results show that the nano-SiC particles can significantly refine the microstructure of Mg-9Al alloy.When nanoparticles are added at 1.0vol.%,the most significant refinement of the composite grain structure is(71.9±28)μm,which is about 63%reduction in grain size compared to the matrix alloy.Moreover,the dispersion mechanism of nanoparticles in the magnesium matrix is mainly along the grain boundary distribution ofα-Mg with a small amount of intracrystalline distribution.At the same time,it is revealed that the grain refinement mechanism involves the rapid adsorption of nanoparticles located at the grain boundarieson the surface of the growingα-Mg grains,which effectively inhibits the diffusion of solute elements and significantly reduces the growth rate of dendrites.This leads to an increase in the composition subcooling of the melt,reducing the release of latent heat of crystallisation.As a result,more heterogeneous nucleation sites are activated,which increases the nucleation rate of the magnesium alloy and obtains significant grain refinement.

关 键 词：复合材料 Mg-9Al合金 纳米SIC颗粒 铸造 晶粒细化 

分 类 号：TG111.4[金属学及工艺—物理冶金]