Microstructural and mechanical properties of binary Ni–Si eutectic alloys
Microstructural and mechanical properties of binary Ni–Si eutectic alloys
复制标题
DOI：
10.1016/j.jallcom.2014.12.058
复制
发表时间：
2015-09
影响因子：
6.2
通讯作者：
M. Gogebakan;Celal Kursun;K. O. Gunduz;M. Tarakci;Y. Gencer
中科院分区：
文献类型：
--
作者：
M. Gogebakan;Celal Kursun;K. O. Gunduz;M. Tarakci;Y. Gencer
本文采用真空/氩气保护电弧熔炼法制备了名义成分为Ni 80 Si 20、Ni 70 Si 30、Ni 55 Si 45和Ni 45 Si 55（Ni和Si的纯度为99.99%）的Ni-Si共晶合金。研究了Si/Ni比对Ni-Si共晶合金的显微组织、热转变行为、显微硬度和磁性能的影响。采用X射线衍射（XRD）、光学显微镜（OM）、扫描电子显微镜（SEM）、差热分析（DTA）、维氏显微硬度计和振动样品磁强计（VSM）对合金进行了表征。根据常规凝固共晶Ni-Si合金的Ni-Si相图预测的相与本研究中XRD检测到的相相当一致。定量分析结果表明，合金的化学成分与共晶成分非常接近，显微组织为典型的片层共晶形貌。Ni 70 Si 30合金的显微硬度最高，为1126 HV，是Ni-Si共晶中熔化温度最高的合金。显微硬度值随Si/Ni比的增加而降低。Ni 80 Si 20和Ni 55 Si 45合金是软磁合金，Ni 70 Si 30和Ni 45 Si 55合金是顺磁合金，没有磁饱和。
In the present work, Ni–Si eutectic alloys with nominal compositions of Ni80Si20, Ni70Si30, Ni55Si45and Ni45Si55(Ni and Si with the purity of 99.99%) were prepared by arc melting method under vacuum/argon atmosphere. The effects of Si/Ni ratio on the microstructural properties, thermal transformation behavior, micro-hardness and magnetic properties of the Ni–Si eutectic alloys were investigated. These alloys were characterized by X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), differential thermal analysis (DTA), Vickers microhardness measurement and Vibrating Sample Magnetometer (VSM). The phases expected according to Ni–Si phase diagram for conventional solidified eutectic Ni–Si alloys are considerably consistent with phase detected by XRD in this study. The quantitative results confirm that the chemical composition of the alloys very close to eutectic compositions and the microstructures are in typical lamellar eutectic morphology. The maximum microhardness value of 1126 HV obtained for Ni70Si30alloy which has highest melting temperature amongst Ni–Si eutectics. The microhardness values decreases with increase of Si/Ni ratio. Ni80Si20and Ni55Si45alloys are soft ferromagnetic, Ni70Si30and Ni45Si55alloys are paramagnetic with no magnetic saturation.