Abstract: A new in-situ reactive system of Al-Zr(CO3)2 is used to prepare(Al3Zr+Al2O3)p/Al composites by melt method reaction. The XRD and SEM analysis indicate that the particles formed are fine Al3Zr and Al2O3, which are well distributed in the aluminum matrix. The ultimate tensile strength and yield strength are improved by increasing the volume fraction of the particle. The tensile properties are σb=148.3MPa and σs=110.5MPa when the particle volume fraction is 10%. But the elongation goes up firstly but then decreases. Crack initiation and propagation were observed by in-situ tensile experiment. The crack initiation and propagation can be interpreted with dislocation action mechanism and voids necleation and growth mechanism.
Mechanical properties and crack behavior of in-situ composites synthesized in Al-Zr (CO3) 2 reaction system
Abstract：
A new in-situ reactive system of Al-Zr (CO3) 2 is used to prepare (Al3Zr+Al2O3) p/Al composites by melt method reaction. The XRD and SEM analysis indicate that the particles formed are fine Al3Zr and Al2O3, which are well distributed in the aluminum matrix. The ultimate tensile strength and yield strength are improved by increasing the volume fraction of the particle. The tensile properties are σb=148.3 MPa and σs=110.5 MPa when the particle volume fraction is 10%. But the elongation goes up firstly but then decreases. Crack initiation and propagation were observed by in-situ tensile experiment. The crack initiation and propagation can be interpreted with dislocation action mechanism and voids necleation and growth mechanism.
图1 (Al3Zr+Al2O3) p/Al复合材料的SEM组织 Fig.1 SEM microstructures of (Al3Zr+Al2O3) p/Al composites (a) —Distribution of particles; (b) —Morphology of particles
图2 Al-Zr (CO3) 2体系 反应生成相的X射线衍射谱 Fig.2 XRD spectrum of reactants of Al-Zr (CO3) 2 system
图3 (Al3Zr+Al2O3) p/Al复合材料的 室温拉伸性能与初始Zr (CO3) 2含量的关系 Fig.3 Relations of room temperature tensile properties of (Al3Zr+Al2O3) p/Al composites with volume fraction of original Zr (CO3) 2
图5 主裂纹扩展前方遇到颗粒密集区的扩展过程 Fig.5 Main crack growth route encountering particle accumulation zone (a) —Particle compact district before crack extension; (b) —Bottleneck in crack
图6 新裂纹萌生与主裂纹贯通 Fig.6 New crack initiation connected with main crack (a) —Hindrance of main crack propagation; (b) —New crack connected with main crack
图7 颗粒处孔洞的成核、长大而 引起的裂纹萌生、长大模型 Fig.7 Schematic diagram of crack initiation and propagation caused by nucleation and growth of voids near particles (a) —Nucleation process of voids near particles; (b) —Growth of voids near particles; (c) —Formation of crack
