利用光学显微镜、扫描电镜、能谱仪、万能材料试验机等设备，研究了Al-5Ti-0.2C细化剂质量分数和细化保温时间对5356铝合金显微组织和力学性能的影响。结果表明：Al-5Ti-0.2C细化剂能够明显地细化5356铝合金晶粒；随着细化剂质量分数的增加和细化保温时间的延长，铝合金晶粒尺寸先减小后增大；添加细化剂后，铝合金的力学性能得到提高，当细化剂质量分数为0.3%和细化保温20 min时，铝合金的伸长率最大，为12.58%，其综合力学性能最好。

Effect of mass fraction of Al-5Ti-0.2C refiner and refinement holding time on the microstructure and mechanical properties of 5356 aluminum alloy was studied by using optical microscope, scanning electron microscope, energy disperse spectroscopy and universal material testing machine. The results show that the grain of 5356 aluminum alloy was refined significantly after adding Al-5Ti-0.2C refiner. With the increase of refinement holding time and mass fraction of refiner, the grain size of aluminum alloy decreased first and then increased. The mechanical properties of aluminum alloy were improved after adding the refiner. When the mass fraction of refiner was 3% and refining for 20 min, the elongation of the aluminum alloy was the largest, which was 12.58%, and the aluminum has the best comprehensive mechanical properties.