粗铝颗粒对Al_(2)O_(3p)/7075铝基复合材料力学性能影响

Effects of Coarse Aluminum Grain on Mechanical Properties of Al_(2)O_(3p)/7075 Aluminum-based Composites

研究了粗铝颗粒含量对纳米Al_(2)O_(3p)/7075铝基分级构型复合材料力学性能的影响。采用粉末冶金法将7075铝合金细粉(约5μm)和纳米Al_(2)O_(3)颗粒进行高能球磨,再加入0~15%的7075铝粗颗粒进行普通球磨,压坯后真空烧结,最后进行挤压制得复合材料,在室温下测试其压缩性能和硬度。结果表明,随着粗颗粒增加,复合材料的抗压强度缓慢降低,但断裂应变显著提高;其中,粗颗粒含量为15%的复合材料强度和硬度分别比无粗颗粒的降低5.0%和7.2%,但塑性提高了27.6%。因此,在纳米陶瓷颗粒增强铝基复合材料中加入基体粗颗粒制备的分级构型复合材料,明显改善了复合材料的塑性。

The effects of the content of coarse aluminum grains on the mechanical properties of nano-Al_(2)O_(3p)/7075 aluminum-based composites were investigated.Fine powder(~5μm)of 7075 alloy and nanometer Al_(2)O_(3)particles were high-energy ball milled through powder metallurgy method,and mixed with 7075 coarse aluminum particles of 0~15%for ordinary ball milling.After compacting and vacuum sintering and finally extrusion,the composites were fabricated.The compressive properties and hardness of the composites were tested at room temperature.The results indicate that as the content of coarse grains increases,the compressive strength of the composites is slightly decreased,while the elongation is increased obviously,where the compressive strength and hardness of composite containing 15%coarse grain are 5.0%and 7.2%lower than those of one without coarse grains,respectively,while the elongation is 27.6%higher.Therefore,the plasticity of composites is improved obviously by adding hierarchical structured composites that are manufactured by adding coarse matrix particles into nano ceramic particles reinforced aluminum matrix composites.