Ideal shear strength and deformation behaviours of L1₀ TiAl from first-principles calculations

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• 作者：PING-YING TANG ; GUO-HUA HUANG ; QING-LIAN XIE ; JIAN-YING LI
• 关键词：First ; principles calculations ; ideal shear strength ; deformation mode ; charge density ; density of states.
• 刊名：Bulletin of Materials Science
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：39
• 期：6
• 页码：1411-1418
• 全文大小：7,357 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Materials Science
  Engineering, general
  
• 出版者：Springer India
• ISSN：0973-7669
• 卷排序：39

文摘

The stress–strain relationships for four different shear processes of L1₀ TiAl have been investigated from first-principles calculations, and the peak shear stresses in these slip systems were obtained. By analysing the structural unit cell, bond length and charge density, the deformation modes under shear were elaborately discussed. Both of the peak shear stresses and the charge density indicate that the ideal shear strength of L1₀ TiAl occurs in the \(\boldsymbol {\langle \! 11\bar {2} ]\{111\}}\) direction. It is shown that some bonds are enormously stretched accompanying with depletion of charge density as the strain increase. The density of states was studied in detail. It is indicated that strong hybridization exists between Ti 3 d and Al 2 p, and the structural stability would be lowered with increase of the strain.