(華南理工大學 國家金屬材料近凈成形工程技術研究中心,廣州 510640)
摘 要: 混雜顆粒增強鋁基復合材料通過發(fā)揮各增強相的協(xié)同作用,提高其綜合力學性能,具有單一顆粒增強鋁基復合材料所不具備的優(yōu)勢。本文采用激光選區(qū)熔化(SLM)技術制備了TiC/SiC混雜顆粒增強AlSi10Mg復合材料。通過EBSD、SEM、TEM和拉伸試驗研究了添加TiC、SiC顆粒對復合材料的顯微組織和力學性能的影響。結果表明:TiC的加入,使(TiC+SiC)/AlSi10Mg復合材料的組織由粗大柱狀晶轉變?yōu)榧毿〉牡容S晶,鋁基體平均粒徑僅為4.27 μm。SiC與鋁基體之間發(fā)生輕微的界面反應,生成少量棒狀的Al4C3和Si,界面結合良好。SLM制備的(TiC+SiC)/AlSi10Mg復合材料具有優(yōu)良的力學性能,其伸長率和抗拉強度分別為(9.7±0.4)%、(488±8) MPa,與SLM制備的AlSi10Mg合金相比,分別提高了19.8%和22.0%。TiC/SiC混雜增強鋁基復合材料強度和塑性的提高是多種強化機制共同作用的結果,為采用SLM成形高性能鋁基復合材料及其應用提供技術參考,具有重要的研究意義和應用價值。
關鍵字: 激光選區(qū)熔化;混雜顆粒;鋁基復合材料;強化機制
(National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, China)
Abstract:The hybrid particles reinforced aluminum matrix composite material has excellent mechanical properties, which a single nanoparticle reinforced aluminum matrix composite does not have, through the synergy of the reinforcement phases. In this study, the TiC/SiC hybrid particle reinforced AlSi10Mg composite material was prepared by selective laser melting (SLM) technology. The effects of TiC and SiC particles on microstructures and mechanical properties of composite materials were studied through EBSD, SEM, TEM and tensile tests. The results show that the addition of TiC changes the structure of the (TiC+SiC)/AlSi10Mg composite from coarse columnar grains to fine equiaxed grains, and the average grain size of the aluminum matrix is only 4.27 μm. The interface reaction between SiC and the aluminum matrix produces a small amount of rod-like Al4C3 and Si, and the interface is well bonded. The (TiC+SiC)/AlSi10Mg composite prepared by SLM has excellent mechanical properties. Its elongation and tensile strength are (9.7%±0.4)% and (488±8) MPa, respectively. Compared with those of AlSi10Mg alloy prepared by SLM, they are improved by 19.8% and 22.0%, respectively. The increment in strength and plasticity of TiC/SiC hybrid reinforced aluminum matrix composites is the result of multiple strengthening mechanisms. It provides a technical reference for the use of selective laser melting and forming of high-performance aluminum-based composite materials and their applications. It has important research significance and application value.
Key words: SLM; hybrid particles; aluminum matrix composites; strengthening mechanism


