添加NH4AlO(OH)HC03原位生成Al203/Al复合材料的制备及其性能

摘要

Aluminium matrix composite reinforced by Al2O3 particles was produced by adding NH4AlO(OH)HCO3 into molten aluminum.The mechanical properties and wear behavior of the as-fabricated composites were studied.The results show that during stirring y-Al2O3 particles were formed via decomposition reaction of NH4AlO(OH)HCO3,and the distribution of Al2O3 particles is more uniform in the matrix aluminum than directly added Al2O3 into molten aluminum.The density and the hardness values of the as-fabricated composites increase with increasing the particle volume fraction,while the tensile strength of the composites decreases with increasing the volume fraction of the Al2O3 particles.The wear rate of the composites decreases with increasing the volume fraction of the particle and loading.The in situ formed Al2O3/Al composite by adding NH4AlO(OH)HCO3 shows more superior mechanical and wear behaviors than that prepared by directly adding Al2O3 particles.%碳酸铝铵与熔融的铝液反应原位生成颗粒增强铝基复合材料,对复合材料的力学性能和摩擦磨损行为进行研究.结果表明:在搅拌的铝熔体中碳酸铝铵发生分解反应生成γ-Al2O3；该原位反应的增强颗粒比直接添加的Al2O3在铝熔体中分布得更均匀；复合材料的密度和硬度随着增强相加入量的增加而提高,而强度则随着增强相加入量的增加而降低；磨损率随着增强相加入量的增加和载荷的增加而提高；原位反应生成的复合材料的力学性能和耐磨性明显优于直接添加Al2O3颗粒形成的复合材料的.