Fabrication of a New Model Hybrid Material and Comparative Studies of its Mechanical Properties

Aluminum Foam;Dynamic Compression Testing;Energy Absorption;Mechanical Engineering

Cluff, Daniel Robert Andrew

University of Waterloo

关键词: Aluminum Foam;    Dynamic Compression Testing;    Energy Absorption;    Mechanical Engineering;   

Others  :  https://uwspace.uwaterloo.ca/bitstream/10012/3136/1/Dan_Cluff_MASc_Thesis_sub.pdf

瑞士|英语

来源: UWSPACE Waterloo Institutional Repository

【 摘 要 】

A novel aluminum foam-polymer hybrid material was developed by filling a 10 pore per inch (0.39pores per millimeter), 7 % relative density Duocel® open-cell aluminum foam with a thermoplasticpolymer of trade name Elvax®. The hybrid was developed to be completely recyclable and easy toprocess. The foam was solution treated, air quenched and then aged for various times at 180˚C and220˚C to assess the effect of heat treatment on the mechanical properties of the foam and to choosethe appropriate aging condition for the hybrid fabrication. An increase in yield strength, plateauheight and energy absorbed was observed in peak-aged aluminum foam in comparison with underagedaluminum foam. Following this result, aluminum foam was utilized either at the peak-agedcondition of 4 hrs at 220˚C or in the as-fabricated condition to fabricate the hybrid material.Mechanical properties of the aluminum foam-polymer hybrid and the parent materials were assedthrough uniaxial compression testing at static ( de/dt = 0.008s-1 ) and dynamic ( de/dt = 100s-1 ) loadingrates. The damping characteristics of aluminum foam-polymer hybrid and aluminum foam were alsoobtained by compression-compression cyclic testing at 5 Hz. No benefit to the mechanical propertiesof aluminum foam or the aluminum foam-polymer hybrid was obtained by artificial aging to peakagedcondition compared to as-fabricated foam. Although energy absorption efficiency is notenhanced by hybid fabrication, the aluminum foam-polymer hybrid displayed enhanced yield stress,densification stress and total energy absorbed over the parent materials. The higher densificationstress was indicative that the hybrid was a better energy absorbing material at higher stress than thealuminum foam. The aluminum foam was found to be strain rate independent unlike the hybrid wherethe visco-elasticity of the polymer component contributed to its strain rate dependence. The dampingproperties of both aluminum foam and the aluminum foam-polymer hybrid materials were found tobe amplitude dependant with the hybrid material displaying superior damping capability.