闭孔泡沫Al-Cu填充铝合金薄壁管的低速冲击性能

Low-speed Impact Performance of Closed-cell Al-Cu Foams Filled Thin-walled Aluminum Alloy Tubes

目的研究闭孔泡沫Al-Cu填充铝合金薄壁管在低速冲击载荷下的力学及吸能性能,探究泡沫Al-Cu与铝合金薄壁管之间的交互作用。方法采用粉末冶金发泡法制备闭孔泡沫Al-Cu,并将其直接填充到铝合金薄壁管中,获得闭孔泡沫Al-Cu填充薄壁管(简称“填充管”)。采用万能电子试验机和冲击试验机对试样进行力学及吸能性能测试,采用VIC-3D系统和高速摄像机观察试样的宏观变形行为,采用扫描电子显微镜(SEM)分析试样的微观断口形貌。结果在不同冲击能量下,泡沫Al-Cu具有较稳定的吸能特性。在相同位移下,较大冲击能量下的填充管能够吸收更多能量。与薄壁管相比,受冲击后填充管的形变较小且其冲击曲线更加平稳,表明泡沫Al-Cu芯材的填入能够增强变形稳定性及整体吸能能力。与泡沫Al-Cu相比,填充管受应变率影响较小,可在较宽应变率范围内稳定吸能,较高应变率下的冲击会导致泡孔发生脆性断裂。结论填充泡沫Al-Cu芯材能够提高薄壁管受冲击载荷时的变形稳定性,两者之间的相互作用使填充管结构具有更好的吸能性能。

The work aims to study the mechanical and energy-absorbing properties of closed-cell Al-Cu foams filled thin-walled aluminum alloy tubes under low-speed impact load,and to investigate the interaction between Al-Cu foams and aluminum alloy thin-walled tubes.The closed-cell Al-Cu foams were prepared by powder metallurgical foaming method and filled directly into the thin-walled aluminum alloy tube to obtain the closed-cell Al-Cu foams filled thin-walled tube(referred to as“foam-filled tube”).Electronic universal testing machine and impact testing machine were used to test the mechanical and energy-absorbing properties of the specimens,and the macroscopic deformation behavior of the specimens were observed by VIC-3D system and high-speed camera,and the microscopic fracture morphology of the specimens were analyzed by scanning electron microscope(SEM).The Al-Cu foams had a more stable energy-absorbing properties under different impact energies,but the foam-filled tube absorbed more energy under the same displacement with larger impact energy.Compared with the thin-walled tube,the foam-filled tube had less deformation and had a smoother impact curve after impact,indicating that the filling of the Al-Cu foams increased the stability of deformation and the overall energy-absorbing properties.Compared with Al-Cu foams,the structure of foam-filled tube was less affected by strain rate and could absorb energy stably over a relatively wide range of strain rates and higher strain rate impact could lead to brittle rupture of the cells.The filling of the Al-Cu foams core improves the deformation stability of the thin-walled tube under impact load,and the interaction between the two makes the foam-filled tube structure have better energy-absorbing properties.