Comparative study of mechanical properties of pure nanocrystalline Ni and Ni-Tf nanocomposite

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• 作者：Arnomitra Chatterjee^a ; ^{amitrac@barc.gov.in} ; Garima Sharma^a ; ¹ ; Jalaj Varshney^b ; S. Neogy^a ; R.N. Singh^a
• 关键词：Nanocrystalline Ni ; Nanocomposite ; Nanoindentation ; Tensile test ; Strain-rate sensitivity ; Activation volume
• 刊名：Materials Science and Engineering: A
• 出版年：2017
• 出版时间：27 January 2017
• 年：2017
• 卷：684
• 期：Complete
• 页码：626-633
• 全文大小：2810 K
• 卷排序：684

文摘

Mechanical properties of nanocrystalline (nc) Nickel (Ni) and Ni-Teflon (Ni-Tf) nanocomposite has been studied in detail using nanoindentation and conventional tensile tests. Nanoindentation tests carried out at room temperature over a range of loading rate exhibited higher hardness for the nanocomposite as compared to the nc-Ni due to Tf dispersion. An increase in strain rate sensitivity (SRS) and decrease in activation volume of the nanocomposite as compared to nc-Ni was also observed. Tensile tests were carried out over a temperature regime of room temperature (RT) to 500 °C. Tensile data also showed enhancement of yield stress and ultimate tensile strength up to 150 °C. But from 200 °C and above, Tf dispersion is unable to provide superior strength over nc-Ni as both the materials show almost similar strength. However, the ductility of the Ni-Tf nanocomposite was observed to be higher at all temperature compared to the pure nc-Ni. SRS was found to increase with temperature while SRS in nanocomposite had higher value below 200 °C. The present study reveals that Ni-Tf nanocomposite possess better strength and ductility compared to nc-Ni up to 200 °C.