用原位自生法制备了 Ti Al- B合金 ,并用 XRD、SEM对材料的相组成、微观组织和初生 Ti B2 晶体的界面结构特征进行了研究。结果表明 :该合金主要由 Ti Al和 Ti B2 两相组成 ;初生 Ti B2 呈六面棱柱状 ,在其 (0 0 0 1)面存在清晰的生长...用原位自生法制备了 Ti Al- B合金 ,并用 XRD、SEM对材料的相组成、微观组织和初生 Ti B2 晶体的界面结构特征进行了研究。结果表明 :该合金主要由 Ti Al和 Ti B2 两相组成 ;初生 Ti B2 呈六面棱柱状 ,在其 (0 0 0 1)面存在清晰的生长台阶、凸台状或柱棒状分枝 ,它们的各晶面取向与母体的取向一致。分析表明 ,在 Ti Al- B合金凝固过程中初生 Ti B2 晶体的固 -液界面是不稳定的 ,使固 -液界面由一完整光滑的界面逐渐演变为由多个相互独立的次级界面构成的复杂界面 ,次级界面亦为小面结构。展开更多
A newly designed TiAl alloy containing W,Nb,and B was produced through magnetic-flotation-melting method.Mass production of this TiAl-based alloy,15 kg ingot size,which is quite different from the 0.05 kg small ingot ...A newly designed TiAl alloy containing W,Nb,and B was produced through magnetic-flotation-melting method.Mass production of this TiAl-based alloy,15 kg ingot size,which is quite different from the 0.05 kg small ingot produced by arc-melting,has a large effect on the metallurgical properties,such as the grain size and the phase structures of the alloy.Heat treatments were carefully designed in order to reduce the amount of the high-temperature remaining β phase in the alloy,and to obtain optimal microstructures for mechanical behavior studies.A room-temperature ductility of 1.9% was obtained in the cast TiAl-based alloy after the appropriate heat treatment.The mechanical behavior of the large ingot through mass production of the TiAl-based alloy was largely improved by the alloy design and subsequent heat treatments.展开更多
基金Project(11X-SP173V) supported by the U.S. Fossil Energy Materials ProgramProject supported by the U.S. National Science Foundation Combined Research-Curriculum Development(CRCD) ProgramProject(DE-AC05-00OR-22725 UT-Battelle,LLC) supported by Division of Materials Science and Engineering,Office of Basic Energy Science,U.S.Department of Energy
文摘A newly designed TiAl alloy containing W,Nb,and B was produced through magnetic-flotation-melting method.Mass production of this TiAl-based alloy,15 kg ingot size,which is quite different from the 0.05 kg small ingot produced by arc-melting,has a large effect on the metallurgical properties,such as the grain size and the phase structures of the alloy.Heat treatments were carefully designed in order to reduce the amount of the high-temperature remaining β phase in the alloy,and to obtain optimal microstructures for mechanical behavior studies.A room-temperature ductility of 1.9% was obtained in the cast TiAl-based alloy after the appropriate heat treatment.The mechanical behavior of the large ingot through mass production of the TiAl-based alloy was largely improved by the alloy design and subsequent heat treatments.
