Effects of Si on Structure and Properties of Mg-Sn Alloy
Magnesium alloys are becoming ever more prevalent in automotive and aerospace industries as energy conservation and performance demands increase. However, it is limited on further application in the automotive field for its low strength compared with steel and aluminum alloys. Effects of Si addition on microstructure and mechanical properties of as-cast Mg-5%Sn magnesium alloy were also studied using SEM, XRD and tensile testing. The results show that the phases of as-cast alloy are composed of α-Mg, Mg2Sn; Mg2Si. The addition of Si suppresses the precipitation of the Mg2Sn, Product Chinese character shape phases of Mg2Si. With the increase of Si content, the effect becomes more apparent. When Si content is up to 1.25wt%, the grain refining effect reached best level. The average alloy grain size reduced from 90μm to 30μm, the tensile strength is the highest. The average tensile strength increased from 128 MPa to 156 MPa. When the Si added at 1.25wt% or less, the hardness and strength were improved with the increase of Si. When 1.25% Si was added, grain did not become further refinement. While Si content was continue to be increase, the tensile strength decreased.
Guangming Zhao, Liping Lu, Bin Long and Zunyu Nie
H. R. Geng et al., "Effects of Si on Structure and Properties of Mg-Sn Alloy", Applied Mechanics and Materials, Vol. 320, pp. 303-307, 2013