上海交通大学学报(英文版) ›› 2012, Vol. 17 ›› Issue (6): 648-652.doi: 10.1007/s12204-012-1339-0

• 论文 • 上一篇    下一篇

Microstructure and Hardness of Ni-xSi Alloys

LIU Li1,2* (刘礼), MA Xiao-li1 (马晓丽), ZHAO Su3 (赵素)   

  1. (1. School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200240, China; 2. School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai 200240, China; 3. School of Mechanical Engineering, Shanghai Dianji University, Shanghai 200240, China)
  • 出版日期:2012-12-31 发布日期:2012-12-30
  • 通讯作者: LIU Li1,2* (刘礼) E-mail:liuli198144@gmail.com

Microstructure and Hardness of Ni-xSi Alloys

LIU Li1,2* (刘礼), MA Xiao-li1 (马晓丽), ZHAO Su3 (赵素)   

  1. (1. School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200240, China; 2. School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai 200240, China; 3. School of Mechanical Engineering, Shanghai Dianji University, Shanghai 200240, China)
  • Online:2012-12-31 Published:2012-12-30
  • Contact: LIU Li1,2* (刘礼) E-mail:liuli198144@gmail.com

摘要: The microstructure and hardness of conventionally solidified Ni-xSi (x = 21.4%, 22%, 24%, 26%) alloys were investigated. The solidification microstructures of different Ni-Si alloys were observed by optical microscope (OM) and scanning electron microscope (SEM) and the phase composition was indentified under the help of energy dispersive X-ray (EDX) analysis. The macro- and micro-hardness of the Ni-Si alloys at room temperature were also examined. The experimental results indicated that both the microstructure and hardness closely depended on the Si content. Due to the vast formation of primary γ-Ni31Si12 phase, the hardness of Ni-26.0%Si alloy was significantly improved compared with that of Ni-21.4%Si eutectic alloy. However, the fracture toughness was greatly weakened simultaneously. The (β1-Ni3Si+γ-Ni31Si12) lamellar eutectoid structure formed in the primary γ-Ni31Si12 phase exhibited better ductility than single γ-Ni31Si12 phase at the cost of relatively small hardness reduction.

关键词: Ni-Si alloy, intermetallic compound, microstructure, hardness

Abstract: The microstructure and hardness of conventionally solidified Ni-xSi (x = 21.4%, 22%, 24%, 26%) alloys were investigated. The solidification microstructures of different Ni-Si alloys were observed by optical microscope (OM) and scanning electron microscope (SEM) and the phase composition was indentified under the help of energy dispersive X-ray (EDX) analysis. The macro- and micro-hardness of the Ni-Si alloys at room temperature were also examined. The experimental results indicated that both the microstructure and hardness closely depended on the Si content. Due to the vast formation of primary γ-Ni31Si12 phase, the hardness of Ni-26.0%Si alloy was significantly improved compared with that of Ni-21.4%Si eutectic alloy. However, the fracture toughness was greatly weakened simultaneously. The (β1-Ni3Si+γ-Ni31Si12) lamellar eutectoid structure formed in the primary γ-Ni31Si12 phase exhibited better ductility than single γ-Ni31Si12 phase at the cost of relatively small hardness reduction.

Key words: Ni-Si alloy, intermetallic compound, microstructure, hardness

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