Al-K_2ZrF_6体系熔体反应法合成复合材料的微观组织和力学性能  

Microstructure and Mechanical Properties of Composites Synthesized by Direct Melt Reaction in the Al-K_2ZrF_6 System

作　　者：汪小燕[1] 赵玉涛[1] 陈刚[1] 程晓农[1] 张红杰[1] 章照[1] 

机构地区：[1]江苏大学,江苏镇江212013

出　　处：《稀有金属材料与工程》2007年第2期259-263,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金项目(50471050);江苏省高技术研究项目(BG2005026);高校高技术产业化发展项目(JH02-039);铝基复合材料工程技术研究中心研发基金项目(BM2003014)

摘　　要：开发了Al-K2ZrF6体系熔体反应法合成原位铝基复合材料,采用XRD,SEM和TEM分析了复合材料中相组成、微观组织和界面结构。实验结果表明:合成的增强相为Al3Zr颗粒,常规金属型铸造的复合材料中其尺寸在3μm～4μm左右,一般成聚集态分布,颗粒形貌基本为长方体状;该复合材料经重熔快淬成形后,颗粒尺寸减小,基本为粒状,并弥散分布于基体上。Al3Zr/Al复合材料的界面结构研究表明,Al3Zr颗粒与Al存在一定的晶体学位向关系:[221]Al3Zr∥[100]Al,(012)Al3Zr∥(110)Al,其点阵错位度仅为10.87%,这表明Al3Zr颗粒可作为基体Al相的形核衬底。Al3Zr/Al复合材料的力学性能测试显示,当Al3Zr颗粒体积分数为11.2%时,抗拉强度和屈服强度分别为148.7MPa和110.2MPa,而且Al3Zr/Al复合材料的抗拉强度和屈服强度均随颗粒体积分数增加显著提高。A novel in-situ particulate reinforced aluminum matrix composite has been successfully developed by direct melt reaction （DMR） technique in the Al-K2ZrF6 system. Phase composition, morphology and interface microstructure in the composite were investigated by scanning electron microscope （SEM）, X-ray diffraction （XRD）, and transmission electron microscopy （TEM）. The experimental results indicate that the reinforcement phase synthesized in the Al-K2ZrF6 system is Al3Zr particle. The size of Al3Zr particle is about 3 μm-4 μm. The micro-morphology of Al3Zr particle is mainly in the shape of rectangle under the condition of conventional permanent mould casting. But, after the same composite is re-molten and formed by rapid solidification, the size of Al3Zr is reduced significantly and well-distributed in aluminum matrix in the shape of polyhedron. The interfacial structure of Al3Zr/Al was analyzed by transmission electron microscopy （TEM）. The result shows that there is a crystallographic orientation relationship of [^-2^-21]Al3Zr∥[100]Al and （012）Al3Zr∥（1^-10）Al. Therefore, it may be concluded that the matrix Al phase can nucleate on the substrate Al3Zr particles with a small lattice mismatch 10.87%. The tensile strength and yield strength of Al3Zr/Al composites are σb= 148.7 MPa and σy=110.2 MPa, respectively, when the particle volume fraction is 11.2%. Furthermore, the tensile strength and yield strength of Al3Zr/Al composites are both improved with the increasing of Al3Zr particulate volume fraction.

关 键 词：Al-K2ZrF6体系 熔体反应法 原位复合材料 微观组织 力学性能 

分 类 号：TB331[一般工业技术—材料科学与工程]