樊利娜
,
寇宏超
,
钟宏
,
张铁邦
,
李金山
稀有金属材料与工程
以Ti47Al二元合金为研究对象,探讨了硼添加及冷却速度对合金α→γ+α2相变的影响规律.结果表明,添加0.5at％B显著细化了Ti47Al合金的片层团组织,Ti47Al合金中块状组织主要在原始α晶界上形核,还有少量的在晶内形核;添加硼可以促进块状转变的发生,这是由于硼化物有效细化了原始α晶粒,还与固溶的硼元素有关.添加硼可以提高片层组织形成的临界冷速,抑制羽毛状组织和魏氏组织的形成.
关键词:
TiAl合金
,
硼添加
,
固态相变
,
块状组织
Wen DENG Liangyue XIONG Chiwei LUNG International Centre for Materials Physics
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
ChinaShuhe WANG Jianting GUO Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
China
材料科学技术（英文）
The electronic structure of Ni_3Al alloys with different B contents has been investigated by measuring the positron lifetime spectra.The segregation of B atoms to defects could form strong covalent bondings with Ni and Al atoms and make the electronic structure in those locations similar to that in bulk,thus strengthen their cohesion.The interaction of B atoms,which were solid-solutioned in the crystal lattice of Ni_3Al in a manner of occupying interstitial sites,with Ni and Al atoms resulted in the increase of the density of valent electrons,thus increased the bonding cohesion in bulk.The im- provement of the mechanical properties of Ni_3Al alloys by B doping was due to both“grain bounda- ry effect”and“bulk effect”of B,which correlated with their electronic structure.
关键词:
electronic structure
,
null
,
null
,
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