Effect of Deformation Conditions on the Dynamic Mechanical Behaviour of Mg-Gd-Y-Nd-Zr Alloys
The dynamic impact mechanical deformation behavior of the Mg-8Gd-3Y-0.5Nd-0.5Zr alloy in its peak aging extruded state at deformation temperature and strain rate was investigated by means of observation metallographic(OM),scanning electron microscopy(SEM),energy dispersive spectrum(EDS),microhardness testers,and a split Hopkinson pressure bar(SHPB)methods.The results show that the alloy reaches peak aging at 220 ℃/14 h and its hardness is about 143.2 HV,which is an improvement of about 55％.The alloys show excellent impact resistance at different deformation temperatures,with compressive strengths of up to 682 MPa at room temperature and a strain rate of 3 000 s-1;635 MPa at 100 ℃ and a strain rate of 1 500 s-1;and 583 MPa at 400 ℃ and a strain rate of 3 000 s-1.The excellent impact resistance of the alloys at different temperatures is mainly due to the synergistic strengthening mechanism of the age-strengthened phases,the stabilized massive rare-earth-rich(REH)particles,and the dynamic precipitation phases formed at grain boundaries during the impact process.As the strain rate and deformation temperature increase,the thermal softening effect of the alloy increases and the mechanical properties of the alloy decrease.
NETL
NSTL
万方数据
维普
