The influences of slight amount of B element on the microstructure and properties of AlCoCrFeNiBx high entropy alloys(x = 0,0.01,…,0.09 and 0.1,mole fraction) were investigated.The AlCoCrFeNi high entropy alloy exh...The influences of slight amount of B element on the microstructure and properties of AlCoCrFeNiBx high entropy alloys(x = 0,0.01,…,0.09 and 0.1,mole fraction) were investigated.The AlCoCrFeNi high entropy alloy exhibits equiaxed grain structures with obvious composition segregation.However,with the addition of B element,the alloys exhibit dendrite structures.Inside the dendrites,spinodal decomposition structure can be clearly observed.With the addition of B element,the crystal structures change from(B2 + BCC) to(B2 + BCC + FCC) structures,and the hardness firstly increases from HV 486.7 to HV 502.4,then declines to HV 460.7(x ≥ 0.02).The compressive fracture strength firstly shows a trend of increasing,and then declining(x ≥ 0.08).The coercive forces and the specific saturation magnetizations of the alloys decrease as B addition contents increase,the decreasing coercive forces show a better soft magnetic behavior.展开更多
The phase evolution in (88%-91%)Mg-8%Sn-l%Zn-X (X=A1, Mn and/or Ce) system was analyzed via CALPHAD method and simulations were used in precise selection of the chemical composition. The influence of the addition ...The phase evolution in (88%-91%)Mg-8%Sn-l%Zn-X (X=A1, Mn and/or Ce) system was analyzed via CALPHAD method and simulations were used in precise selection of the chemical composition. The influence of the addition of different alloying elements such as A1, Mn and Ce on the microstructure and microhardness of Mg-8%Sn-l%Zn-based alloys was investigated. Combined addition of A1 and Mn shows features distinct from separate addition of A1 or Mn. Additions of l%AI and l%Mn to base alloy result in the formation of massive A1-Mn phase in a-Mg matrix grains. Addition of Ce element can refme the second eutectic precipitates and form intermetallic compounds with Sn. Fine rod-like Sn-Ce phase presents mainly on the grain boundaries and plays a role in inhibiting grain growth. The effects of alloying elements on Vickers microhardness and indentation size effect of base alloy were examined.展开更多
基金Projects(51134013,51104029,51471044)supported by the National Natural Science Foundation of ChinaProject supported by the Fundamental Research Funds for the Central Universities,China+1 种基金Project(LZ2014007)supported by the Key Laboratory of Basic Research Projects of Liaoning Province Department of Education,ChinaProject(2014028013)supported by the Natural Science Foundation of Liaoning Province,China
文摘The influences of slight amount of B element on the microstructure and properties of AlCoCrFeNiBx high entropy alloys(x = 0,0.01,…,0.09 and 0.1,mole fraction) were investigated.The AlCoCrFeNi high entropy alloy exhibits equiaxed grain structures with obvious composition segregation.However,with the addition of B element,the alloys exhibit dendrite structures.Inside the dendrites,spinodal decomposition structure can be clearly observed.With the addition of B element,the crystal structures change from(B2 + BCC) to(B2 + BCC + FCC) structures,and the hardness firstly increases from HV 486.7 to HV 502.4,then declines to HV 460.7(x ≥ 0.02).The compressive fracture strength firstly shows a trend of increasing,and then declining(x ≥ 0.08).The coercive forces and the specific saturation magnetizations of the alloys decrease as B addition contents increase,the decreasing coercive forces show a better soft magnetic behavior.
文摘The phase evolution in (88%-91%)Mg-8%Sn-l%Zn-X (X=A1, Mn and/or Ce) system was analyzed via CALPHAD method and simulations were used in precise selection of the chemical composition. The influence of the addition of different alloying elements such as A1, Mn and Ce on the microstructure and microhardness of Mg-8%Sn-l%Zn-based alloys was investigated. Combined addition of A1 and Mn shows features distinct from separate addition of A1 or Mn. Additions of l%AI and l%Mn to base alloy result in the formation of massive A1-Mn phase in a-Mg matrix grains. Addition of Ce element can refme the second eutectic precipitates and form intermetallic compounds with Sn. Fine rod-like Sn-Ce phase presents mainly on the grain boundaries and plays a role in inhibiting grain growth. The effects of alloying elements on Vickers microhardness and indentation size effect of base alloy were examined.