In situ investigation of deformation mechanisms in magnesium-based metal matrix composites

Abstract

We studied the effect of short fibers on the mechanical properties of a magnesium alloy. In particular, deformation mechanisms in a Mg-Al-Sr alloy reinforced with short alumina fibers were studied in situ using neutron diffraction and acoustic emission methods. The fibers' plane orientation with respect to the loading axis was found to be a key parameter, which influences the acting deformation processes, such as twinning or dislocation slip. Furthermore, the twinning activity was much more significant in samples with parallel fiber plane orientation, which was confirmed by both acoustic emission and electron backscattering diffraction results. Neutron diffraction was also used to assist in analyzing the acoustic emission and electron backscattering diffraction results. The simultaneous application of the two in situ methods, neutron diffraction and acoustic emission, was found to be beneficial for obtaining complementary datasets about the twinning and dislocation slip in the magnesium alloys and composites used in this study.

Metal Matrix Composites

“…Taking into account the lower volume fraction of the strengthening fibers/particles and the lower strengthening contribution of particles to the load transfer, the calculated value~30 MPa seems to be a good approximation of the load transfer real value for the studied composite. Mean residual stresses in the matrix were measured in magnesium-based MMCs by Farkas et al ex situ [62] and in situ using neutron diffraction [61,63]. They found a higher <σ m > max than that of the calculated estimation according to the equation reported in Table 3.…”

“…Cu [49,50], Ag [51], Ni [52], AgPd [53], Al [54], and AlCu [55] In-situ chemical synthesis In this method, CNTs are directly synthesized from the vapor phase on the metallic powders. Mg [56], FeCr [57], Cu [58], AlCu [59], Al [60], and Fe [61] Cu [62], Ni [63], Al [64], Au, and Pt [65] Electrodeposition In this method, CNTs are embedded in an electrochemically formed metallic film. This film is deposited as metallic ions transfer from cathode or electrolyte solution to the anode.…”

Elastic and Plastic Behavior of the QE22 Magnesium Alloy Reinforced with Short Saffil Fibers and SiC Particles

“…Taking into account the lower volume fraction of the strengthening fibers/particles and the lower strengthening contribution of particles to the load transfer, the calculated value ~30 MPa seems to be a good approximation of the load transfer real value for the studied composite. Mean residual stresses in the matrix were measured in magnesiumbased MMCs by Farkas et al ex situ [62] and in situ using neutron diffraction [61,63]. They found a higher <σm>max than that of the calculated estimation according to the equation reported in Table 3.…”

Synthesis and characterisation of magnesium matrix composite reinforced with titanium dioxide nanoparticulates

“…Reinforcement of magnesium matrix with large volume proportions of hard ceramic/metallic nanoparticulates always improves the morphological, mechanical, thermal and tribological properties of composite. The fabrication of magnesium matrix composite reinforced with ceramic nanoparticles using stir casting, squeeze casting, spray forming, DMD and powder metallurgy has been reported in [1][2][3][4][5][6][7][8]. However, the low stiffness, poor formability and poor corrosion resistance of magnesium based alloys and its composites hinder their use in wet environment and different structural applications.…”