(1. 清华大学 机械工程系，北京 100084；
2. 清华大学 教育部先进成形制造重点实验室，北京100084)
摘 要: 基于吹气法制备A356基泡沫铝工艺，采用高速搅拌并分批连续加入粉末的方式，避免熔体中颗粒分布不均匀的问题；采用静置吹气头通入压缩空气发泡，通过设计和控制气路，制备出不同孔径、不同壁厚、稳定的泡沫铝。结果表明：A356基泡沫铝是一种典型的塑性泡沫材料，泡孔呈十四面体形状，泡壁较薄，厚度小于150 μm，可控的泡孔平均直径范围很宽，为10~25 mm；泡沫铝在致密化阶段的塑性变形量可达70%以上；不作任何预处理的泡沫铝在高频率声波下的吸声系数可达0.9以上；在泡沫样品后设置0~70 mm空腔，其在低频率声波下的吸声性能显著提高；所制备的泡沫铝具有较好的声学性能和力学性能。
关键字: 泡沫铝；吹气法；力学性能；声学性能
（1. Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;
2. Key Laboratory for Advanced Materials Processing Technology, Ministry of Education,
Tsinghua University, Beijing 100084, China）
Abstract:The A356 alloy foams were fabricated by gas injection method. The high-speed stirring and continuous addition of Al2O3 particles were used to solve the problems of non-uniform distribution of Al2O3 particles. The static orifices were designed to blow the compressed air into the aluminum melt by controlling the gas circuit. The stable aluminum foams with different cell sizes and thicknesses were obtained. The compression test results reveal that the A356 alloy foams have typical plastic deformation characters. The pores of aluminum foams are tetrakaidecahedron with thin walls (<150 μm) and the foams with pore sizes of 10−25 mm can be produced. The strain of the plastic deformation of the aluminum foams can reach more than 70% under compression test. The sound absorption coefficient of aluminum foam without any pretreatment at the high frequency of the sound wave can reach 0.9. After setting up the cavity back of the foams, the absorption coefficient can be improved obviously under low frequency waves.
Key words: aluminum foam; gas injection method; mechanical property; acoustic property
