Effect of long-period-stacking-ordered phases on the microstructure and mechanical properties of carbon fiber reinforced magnesium-gadolinium-zinc composite

Abstract

Abstract In this study, long-period-stacking-ordered (LPSO) phases were introduced to carbon fiber reinforced magnesium-gadolinium-zinc (Cf/Mg-Gd-Zn) composite by adding Gd and Zn with the atomic rate of 2:1 into the matrix, and a new and practical method of design and optimize the interfacial structure was found. The Cf/Mg-Gd-Zn composite was fabricated by pressure infiltration method, and the influence of the LPSO phases on the microstructure and mechanical properties were investigated. LPSO phases were precipitated both at the interface and in the matrix. The LPSO phases at the interface were long rod-like, whose preferential growth direction was almost perpendicular to the axis of carbon fibers. But the LPSO phases formed in the matrix tended to be long and short rod-like, and arranged in a certain angle with the axis of the adjacent carbon fiber. Because of the LPSO phases, the interfacial structure of the composites was significantly optimized. Therefore, the mechanical properties of Cf/Mg-Gd-Zn composite were improved considerably. Specifically, compared with Cf/Mg composite, the interlaminar shear strength and bending strength of Cf/Mg-Gd-Zn composite were improved by 26.4% and 25.7%, respectively.