铸造钛铝合金组织与力学性能

根据对钛铝合金铸态组织的金相观察，分析了合金元素Ｃｒ，Ｖ，Ｎｂ对铸锭组织的影响。研究发现，合金元素Ｃｒ，Ｖ有利于柱状晶生长，在这种柱状晶组织中γ／α２层片排列具有较强的择优取向，即层片界面垂直于柱状晶生长方向；而Ｎｂ抑制柱状晶生长，且含Ｎｂ的ＴｉＡｌ合金宏观等轴晶区和柱状晶区内层片组织均由等轴状的层片团构成，并以四点弯曲试验结果对不同合金化条件的钛铝合金的力学性能的方向性做了评价。

MICROSTRUCTURES AND MECHANICAL PROPERTIES OF CAST TiAl ALLOYS

The effects of alloying elements,Cr,V,Nb,on the cast microstructure have been analyzed on the basis of the metallographical observations of the cast microstructures in several TiAl alloys.It is found that the TiAl alloys alloyed with V and/or Cr tend to form the columnar crystal macrostructure and exhibit preferredly arranged lamellar microstructures under certain casting conditins.The TiAl alloys containing Nb can have equiaxed macrostructures and homogeneous fully lamellar microstructures on the same casting conditions.The mechanical properties of the cast alloys have been evaluated by the 4 point bending test as well.