Comparison of Carbon fibers reinforced Magnesium matrix composites realized by liquid immersion with C-Al and C-Ni pre-treated yarns.

C-Mg composites offer the opportunity for a significant weight reduction compared to C-Al composites. However, the poor wettability of the carbon fibers by magnesium alloys represent an important challenge for the production of such composites. In this study, two approaches are investigated in order to favour a better wetting and to obtain a well-infiltrated C-Mg composites. First, an optimization of a pre-treatment of the C fibers with K_2 ZrF_6 aqueous solution for pre-impregnated C-Al composites [1]. Second, a development of electroless nickel plating technique on C fibers [2]. This study propose an optimization of the two above mentioned techniques and a comparison of the resulting samples. The C-Al yarns are made successively by the following steps: desizing of the fiber by thermal treatment, dipping in a supersaturated and heated aqueous solution of K2ZrF6, drying in a high temperature oven. For each steps, time and temperature are key parameters to optimize. The reactivity between the pre-treated K2ZrF6 fibers and the aluminum is verified by Differential Scanning Calorimetry. The C-Ni yarns are desized and then dipped in an acid or basic heated solution to perform auto-catalytic reaction for Nickel deposition. Concentration, pH, temperature and time of this electroless reaction are parameters influencing the quality of the deposit. Both C-Al and C-Ni pre-treated yarns are immersed in liquid a Mg bath to obtain C-Mg composites. The resulting samples are compared in term of wettability of the Mg on the pre-treated fibers and in term of quality of infiltration inside the yarn.

[1] Anne Mertens et al. Processing of carbon fibers reinforced Mg matrix composites via pre-infiltration with Al. JMEPEG (2012) 21:701-706
[2] Mordechay Schlesinger and Milan Paunovic. Modern electroplating. 5th edition (2014)