Enhancement of magnesium-composite bond-interface by a simple combined abrasion and coating method

Obtaining a strong bond when adhering magnesium alloys to other materials,especially to fiber-reinforced polymer composites,is challenging.Regardless of the strength of the adhesive used,it is the surface preparation that also significantly affects the overall bond strength and long-term performance of the mated surfaces.While optimal and established surface preparations are available for aluminum,steel alloys and polymer composites,the current method proposed for magnesium alloys is extremely onerous,time-consuming,and very expensive.The aim of the research disclosed in this paper has been to develop a relatively simple,effective and economical procedure for enhancing the bond strength between magnesium alloy to fiber-reinforced polymer composites,which had been proven to be a challenging issue.The proposed method facilitates a superior interface-bond using a relatively low-cost epoxy resin.Enhanced Mode I fracture toughness and delamination resistance are obtained.Both static and impact tests are used to assess the effectiveness of the proposed procedure.©2019 Published by Elsevier B.V.on behalf of Chongqing University.

On the Thermal Fatigue of a Room-Cured Neat Epoxy and Its Composite

An experimental investigation is conducted to evaluate the potential degradation in the mechanical properties of an epoxy resin and unidirectional glass fiber-reinforced epoxy (GFRE) as a result of exposure to fluctuating temperature. A commonly used room-cured epoxy resin and the GFRE are subjected to various numbers of thermal cycles (up to 1000 heating/cooling cycles). Mechanical tests are conducted to examine the influence of thermal cycles on the stiffness, ultimate strength and strain of the resin and its GFRE. The Fourier transform-Raman spectroscopy (FT-Raman) is conducted to investigate the influence of the thermal cycles on the resulting chemical changes and curing degree of the resin. In addition, the Differential Scanning Calorimetry (DSC) analysis is conducted to investigate the variation in the glass transition temperature (Tg) of the resin as a function of the applied thermal cycles.