In the present study, the composites have been prepared using vacuum hot pressing process technique. The influence of 2.0 wt.% nanometric SiC particles (n-SiC_p) on the microstructure and fracture mechanism of 7075 aluminum alloy was studied by means of metallographic microscope, scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), laser scanning confocal (LSC). The results indicate that SiC_p fill at grain boundaries dispersing evenly and nail to aluminum grains which sizes have been reduced successfully, that making the organization tighter, the gaps fewer and the surface rougher. Meanwhile, phases (MgZn₂) precipitated from the 7075 aluminum alloy were been detected. The grain bonding states of matrix alloys are strengthened by the combination of fine grains strengthening and dispersion strengthening and thus affect the fracture morphology. The micro-fracture mechanism of 7075 aluminum alloy is micro-porous aggregation fracture, however, the 7075 aluminum matrix composites (AMCs) are quasi cleavage fracture.

在本研究中，使用真空热压工艺技术制备了复合材料。利用金相显微镜，扫描电子显微镜（SEM），能谱仪（EDS），X等研究了2.0 wt。％纳米SiC颗粒（n-SiC _p）对7075铝合金显微组织和断裂机理的影响。射线衍射（XRD），激光扫描共聚焦（LSC）。结果表明，SiC _p填充在晶界处均匀分散，并钉扎到成功减小尺寸的铝晶粒上，这使组织更紧密，间隙更少并且表面更粗糙。同时，相（MgZn ₂检测到从7075铝合金中析出的）。细晶粒强化和弥散强化相结合，强化了基体合金的晶粒结合状态，从而影响了断裂形态。7075铝合金的微断裂机理是微孔聚集断裂，而7075铝基复合材料（AMCs）是准解理断裂。