,Effect of P impurity on mechanical properties of NiAl Σ5 grain boundary: From perspectives of stres

• 作 者: Xue-Lan Hu Ruo-Xi Zhao Jiang-Ge Deng Yan-Min Hu Qing-Gong Song
• 机 构: Sino-European Institute of Aviation Engineering, Civil Aviation University of China, Tianjin 300300,
• 出 处: 中国物理B（英文版）
• 发表日期: 2018年3期
• 关键词: NiAlΣ5 grain boundary P impurity first principles mechanical properties

In this paper,we employ the first-principle total energy method to investigate the effect of P impurity on mechanical properties of NiA1 grain boundary (GB).According to "energy",the segregation of P atom in NiAlΣ5 GB reduces the cleavage energy and embrittlement potential,demonstrating that P impurity embrittles NiAlΣ5 GB.The first-principle computational tensile test is conducted to determine the theoretical tensile strength of NiAlΣ5 GB.It is demonstrated thatthe maximum ideal tensile strength of NiAlΣ5 GB with P atom segregation is 144.5 GPa,which is lower than that of the pure NiAlΣ5 GB (164.7 GPa).It is indicated that the segregation of P weakens the theoretical strength of NiAlΣ5 GB.The analysis of atomic configuration shows that the GB fracture is caused by the interfacial bond breaking.Moreover,P is identified to weaken the interactions between Al-Al bonds and enhance Ni-Ni bonds.