(北京有色金屬研究總院 國家有色金屬復(fù)合材料工程技術(shù)研究中心，北京 100088)
摘 要: 采用粉末冶金法制備15%SiCp/2009Al(體積分數(shù))復(fù)合材料，并測試其旋轉(zhuǎn)彎曲疲勞和軸向疲勞性能，采用掃描電鏡觀察其疲勞斷口。結(jié)果表明：15%SiCp/2009Al復(fù)合材料具有良好的高周疲勞性能，疲勞裂紋萌生于試樣表面中較大的SiC顆粒、金屬間化合物顆粒以及一些“無特殊微觀組織特征”區(qū)域；疲勞裂紋擴展以形成微孔與韌窩、形成撕裂脊、增強顆粒SiC開裂、增強顆粒−基體界面脫粘為主要形式；控制SiC顆粒粒度、優(yōu)化SiC顆粒均勻分布于2009Al基體、保證SiC顆粒與基體具有良好的界面結(jié)合，這樣的微觀組織對 15%SiCp/2009Al復(fù)合材料的疲勞性能至關(guān)重要。
關(guān)鍵字: SiCp/Al復(fù)合材料；疲勞；微觀組織；疲勞斷口
prepared by powder metallurgy process
（National Engineering and Technology Research Center for Nonferrous Metal Composites,
General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract:The fatigue behavior of naturally aged powder metallurgy 15%SiCp/2009Al (volume fraction) composite was investigated. The fatigue lives were determined using load-controlled rotary bending and axial fatigue testing ,the fracture surfaces of samples were examined by scanning electron microscopy. The results show that the high-cycle fatigue properties of 15%SiCp/2009Al composite are superior, the fatigue cracks initiate from several different microstructural defects known as some fractured SiC particles with relatively bigger size at sample surface, intermetallics and so called no specific microstructural feather area. The voids and dimples, tear ridges, SiC particle fracture and SiCp-Al interface decohesion are the main mechanisms during fatigue crack propagation. The microstructure consists of the large size reinforcement, homogeneous distribution of reinforcement and well combination of reinforcement-matrix interface and plays a significant role for fatigue properties of 15%SiCp/2009Al composite.
Key words: SiCp/Al composite; fatigue; microstructure; fracture surface
