Effect Of Different Contents Of Gd And Ni On The Hysteretic And Mechanical Properties Of Mg-Gd-Ni Alloy

Magnesium alloys are widely used in automotive and aerospace applications due to their low density,high specific strength and specific stiffness,good damping and shock absorption properties.Magnesium alloys with long-period stacking ordered(LPSO)structures have unique microstructure and excellent mechanical properties.In this paper,Mg100-4xGd3XNix((at.%)?x=0.4,0.7 and 0.1)alloy was used as the research object to systematically study Regular of the effects of ambient temperature,loading speed and precipitation phase volume fraction on the mechanical properties and hysteretic behavior of the alloy.the results of the study are as follows:With the increase of Gd and Ni alloy elements,the volume fraction of LPSO phase precipitation in as-cast Mg-Gd-Ni alloy increased from 12.8%to 27.7%,while the yield strength of alloy increased from 80MP to 130MPa at room temperature.And the alloy appeared obvious hysteretic behavior,the maximum value of inelastic strain increased by 36%.The hysteretic and mechanical properties of as-cast Mg97 2Gd2.1Ni0.7 alloy show positive loading speed dependence.As the loading speed increased from 0.025 mm/min to 2.5 mm/min,the yield strength increased from 95 MPa to 103 MPa and the inelastic strain maximum increased 22.9%.With the loading temperature increased from 100? to 300 ?,the yield strength of Mg100-4XGd3xNix(x?0.4,0.7 and 1.0)alloys was reduced from(70MPa,82MPa and 113MPa)to(50MPa,60MPa and 73MPa).At the same time,the hysteresis of the as-cast Mg97.2Gd2.1Ni0.7 alloy is weakened,and the maximum value of the inelastic strain is reduced 72.7%.The hysteresis behaviors and mechanical properties of the as-cast Mg97.2Gd2.1Ni0.7 alloy at room temperature show obvious anisotropy.The yield strength along the RD(Rolling Direcrtion,)is 163MPa higher than the TD(Transverse Direction,)of 141MPa;while the hysteresis of TD is more obvious,The inelastic strain maximum of TD is 14.2%higher than RD.With the increase of loading temperature from 100 ? to 300?,the yield strength of the as-rolled Mg97,2Gd2.1Ni0.7 alloy RD and TD was reduced from(160MPa and 138MPa)to(107MPa and 95MPa).The hysteresis of the alloy RD also decreases with the increase of the loading temperature.The maximum value of the inelastic strain reduced 51.6%.No significant inelastic strain was observed at 300?.