(1. 清華大學(xué) 機(jī)械工程系，北京 100084；
2. 清華大學(xué) 教育部先進(jìn)成形制造重點(diǎn)實(shí)驗(yàn)室，北京100084)
摘 要: 基于吹氣法制備A356基泡沫鋁工藝，采用高速攪拌并分批連續(xù)加入粉末的方式，避免熔體中顆粒分布不均勻的問(wèn)題；采用靜置吹氣頭通入壓縮空氣發(fā)泡，通過(guò)設(shè)計(jì)和控制氣路，制備出不同孔徑、不同壁厚、穩(wěn)定的泡沫鋁。結(jié)果表明：A356基泡沫鋁是一種典型的塑性泡沫材料，泡孔呈十四面體形狀，泡壁較薄，厚度小于150 μm，可控的泡孔平均直徑范圍很寬，為10~25 mm；泡沫鋁在致密化階段的塑性變形量可達(dá)70%以上；不作任何預(yù)處理的泡沫鋁在高頻率聲波下的吸聲系數(shù)可達(dá)0.9以上；在泡沫樣品后設(shè)置0~70 mm空腔，其在低頻率聲波下的吸聲性能顯著提高；所制備的泡沫鋁具有較好的聲學(xué)性能和力學(xué)性能。
關(guān)鍵字: 泡沫鋁；吹氣法；力學(xué)性能；聲學(xué)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
