The ω phase is commonly observed in β-Ti alloys and plays a significant role on various properties ofβ-Ti alloys.Although many results about the role of ω phase on mechanical properties of β-Ti alloys have been d...The ω phase is commonly observed in β-Ti alloys and plays a significant role on various properties ofβ-Ti alloys.Although many results about the role of ω phase on mechanical properties of β-Ti alloys have been derived from theoretical and experimental studies,the role of ω phase on deformation mechanism hitherto remains elusive and deserves to be further studied.In this work,the role played by ω phase during the {112} <111>_(β) twining in Ti-Mo alloys were investigated by first-principles calculations at atomic scale.In the energy favorable interface of(112)_(β)(110)_(ω),we found that partial dislocations slipping on the successive(1010)_(ω)planes of ω phase can lead to the formation of {112} <111>_(β) twin nucleus.And the twin nucleus grows inwards ω grain interior through atomic shuffle.Thus,a new twinning mechanism of {112} <111>_(β) assisted by ω phase was proposed.Furthermore,our calculations indicated that the appearance of ITB(interfacial twin boundary) ω phase can improve the stability of the symmetrical{112} <111>_(β) twin boundary(TB),which can well explain the experimental phenomenon that the ITBω phase always accompanies the formation of {112} <111>_(β) twin.Finally,a probable microstructure evolution sequence was suggested,namely β matrix→β matrix+athermal ω phase→(112)[111]_(β) twin+ITB ω phase.Our calculations provide new insights on the role played byω phase during the twinning process of {112} <111>_(β),which can deepen the understanding on the deformation behaviors of β-Ti alloys.展开更多
基金supported by the National Key R&D Program of China(No.2016YFB0701302)the CAS Frontier Science Research Project(No.QYZDJ-SSW-JSC015,QYZDY-SSW-JSC027)+1 种基金supported by the SYNL Basic Frontier&Technological Innovation Research Project(No.L2019R10)the computational support from the Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund(the second phase)under Grant No.U1501501。
文摘The ω phase is commonly observed in β-Ti alloys and plays a significant role on various properties ofβ-Ti alloys.Although many results about the role of ω phase on mechanical properties of β-Ti alloys have been derived from theoretical and experimental studies,the role of ω phase on deformation mechanism hitherto remains elusive and deserves to be further studied.In this work,the role played by ω phase during the {112} <111>_(β) twining in Ti-Mo alloys were investigated by first-principles calculations at atomic scale.In the energy favorable interface of(112)_(β)(110)_(ω),we found that partial dislocations slipping on the successive(1010)_(ω)planes of ω phase can lead to the formation of {112} <111>_(β) twin nucleus.And the twin nucleus grows inwards ω grain interior through atomic shuffle.Thus,a new twinning mechanism of {112} <111>_(β) assisted by ω phase was proposed.Furthermore,our calculations indicated that the appearance of ITB(interfacial twin boundary) ω phase can improve the stability of the symmetrical{112} <111>_(β) twin boundary(TB),which can well explain the experimental phenomenon that the ITBω phase always accompanies the formation of {112} <111>_(β) twin.Finally,a probable microstructure evolution sequence was suggested,namely β matrix→β matrix+athermal ω phase→(112)[111]_(β) twin+ITB ω phase.Our calculations provide new insights on the role played byω phase during the twinning process of {112} <111>_(β),which can deepen the understanding on the deformation behaviors of β-Ti alloys.
