The impact of the multiwall carbon nanotubes on the fatigue properties of adhesive joints of 2024-T3 aluminium alloy subjected to peel

Abstract

The paper presents the results of the research undertaken to determine the impact of the epoxy adhesive nanofiller, in the form of multiwall carbon nanotubes (MWCNT), on the fatigue strength and fatigue lifetime of adhesive joints subjected to peel. Carbon nanotubes were synthesized by means of CVD method with Fe-Co catalysts. Upon the completion of the process, the carbon material was subjected to oxidation and to the acid treatment in order to remove amorphous carbon and catalyst particles. The quantity of 1 wt.% of the dried material was added to epoxy adhesives. Such composition went through the process of mixing, ensuring the adequate nanotubes dispersion. The prepared composition was used to join two elements made of 2024-T3 aluminium alloy.Adhesive joints underwent high-cycle fatigue peel strength tests with the limit number of cycles of 2 million. The tests were carried out on the electromagnetic vibration inductor with the resonance frequency of the flexible adhesive-joined element of about 600 Hz. For each variant, the fatigue curve and fatigue lifetime were determined for a given level of stress. Thanks to adding carbon nanotubes to epoxy adhesives, the possibility of increasing the fatigue strength by 28.9% and the fatigue lifetime by about 477.2% was discovered. The fatigue strength tests were preceded by static T-peel tests.