Effects of (micron+submicron+nano) multisized SiC particles on microstructure and mechanical properties of magnesium matrix composites

Abstract

Many interesting studies on composites with nano or submicron SiCp have been performed since the size advantages of fine SiC particles. However, it is extremely hard to disperse fine particles in metal melts due to their poor wettability and large surface-to-volume ratio, especially the fabrication of composites with multisized SiCp (5 µm, 0.5 µm, and ∼60 nm) is very difficult. The use of multisized reinforcements is required to solve the dispersion problem. The stir casting technology and hot extrusion method could be used to disperse the multisized SiCp in the matrix. The effects of multisized SiCp on the dynamic recrystallization behavior of the composites are discussed. The large-scale dynamic recrystallization caused by adding multisized SiCp results in a fine matrix microstructure. Compared with the as-accepted AZ31B alloy (YS: 195 MPa, UTS: 277 MPa), the yield strength and ultimate tensile strength of the AZ31B/SiCp/n-1 + S-4 + 5-10 composite were enhanced to 73.8 and 44.8%, respectively. The better tensile properties were attributed to the uniform distribution of reinforcement, strengthening effect of multisized SiCp, and grain refinement of magnesium matrix.

Microstructures and mechanical performance of Mg–4Si–6Ni–xY in situ composite after extrusion process

“…One of the most important causes of extensive grain refinement could be dynamic recrystallisation (DRX). During hot deformation, DRX is considerably affected by the size of reinforcement particles and precipitation phases [40,41]. Moreover, during plastic deformation, zones with high-density dislocations are created around micron-sized particles, which are called as the particle deformation zones (PDZs).…”

Effect of B4C reinforcement and hot rolling on microstructure and mechanical properties of WE43 magnesium matrix composite

“…So far, various reinforcing particles such as SiC, SiO 2 , Al 2 O 3, and ZrO 2 have been used to make Mg composites. [12][13][14][15][16] Addition of 0.25 wt% SiC to AZ31 alloy has been reported to modify the microstructure and increase the ultimate tensile strength (UTS) from 250 to 269 MPa. 17 Wang and colleagues investigated the microstructure, physical and mechanical properties of Mg matrix composites with varying amounts of TiB 2 .…”