Development of Small-Scale Impact Three-Point Bending Test Apparatus and Evaluation of Impact Fracture Properties of Mg-6%Al-1%Zn-2% Ca Alloy

摘要

Mechanical properties of magnesium alloys under dynamic loading are still unclear. To evaluate the impact fracture behavior of magnesium alloys, we constructed a novel impact three-point bending test apparatus using three elastic bars with Charpy standard-size specimen, and investigated the impact fracture properties of as-cast Mg-3Al-1Zn (hereafter denoted as AZ31) alloy. Finite element (FE) analysis were carried out to estimate the effect of inertial force of the specimen during the impact three-point bending. Based on the FE analysis, we successfully developed a small-scale apparatus for examining a quarter-size specimen, which was capable of carrying out the impact three-point bending test with minimized influence of the inertial force. Impact fracture behavior of Mg-6Al-1Zn-2Ca (hereafter denoted as AZX612) alloy was estimated and compared by using small-scale apparatus. The experimental results pointed out that the AZX612 had similar energy absorption capability to AZ31 against the dynamic loading, however, the crack propagation speed of the Ca bearing alloy was almost twice as fast as that of the AZ31 alloy.