【摘要】 研究了球形孔通孔和闭孔泡沫铝合金在1MHz-10MHz的超声衰减性能.结果表明:泡沫铝合金的超声衰减性能决定于其孔结构;通孔泡沫铝合金的超声衰减系数a随着孔径d的减小、孔隙率Ps减小和比表面积Sv的增加而增大;闭孔泡沫铝合金的超声衰减系数a随孔径d的减小、孔隙率Ps的增加和比表面积Sv的增加而增大;当孔径d、孔隙率Ps相近时,闭孔泡沫铝合金的超声衰减性能优于通孔泡沫铝合金;在1MHz-10MHz二者是具有良好阻尼性能的轻质材料.其衰减机制为在弹性范围内超声应力波在具有大量孔隙界面的泡沫铝合金中的衰减.更多还原

【Abstract】 Ultrasonic attenuation properties of two kinds of Al alloy foam were studied in the range from 1 MHz to 10 MHz. The results show that the ultrasonic attenuation properties are determined by the pore structures of Al alloy foam. Ultrasonic attenuation coefficient of porous Al alloy increases with decreasing pore diameter, with decreasing porosity and with increasing specific surface. Ultrasonic attenuation coefficient a of cellular Al alloy increases with decreasing pore diameter, with increasing porosity and with increasing specific surface Ultrasonic attenuation property of cellular Al alloy is better than that of porous Al alloy when they have the similar pore diameter and porosity. They are both light materials with good damping properties between 1 MHz and 10 MHz. And the mechanism is that ultrasonic wave is attenuated in the Al alloy foam with a lot of interface in the elastic stage.更多还原