Surface Self-nanocrystallization in Copper Electroforming
- PDF / 11,100,669 Bytes
- 10 Pages / 593.972 x 792 pts Page_size
- 97 Downloads / 221 Views
JMEPEG (2019) 28:211–220 https://doi.org/10.1007/s11665-018-3793-9
Surface Self-nanocrystallization in Copper Electroforming Chunjian Shen, Zengwei Zhu, and Di Zhu (Submitted March 19, 2018; in revised form October 31, 2018; published online December 19, 2018) The coarse columnar grain layer generated on top of electroforming deposits leads to low surface strength and poor global performance of deposits. Here, we introduce a particle abrasive-induced surface selfnanocrystallization process, which is a part of the electroforming process rather than involving complex poststeps using special equipment. It can generate a thickness-controllable surface nanocrystalline layer on top of copper deposits for performance enhancement. In this study, surface nanocrystalline layers of 10, 20, 50 and 120 lm were fabricated on top of 500-lm-thick copper deposits. The tensile strength of copper deposits increases from 234 to 246, 330, 383 and 421 MPa, with a corresponding decrease in elongation from 26 to 25, 24, 15 and 6%, respectively. The moderately thick surface nanocrystalline layer makes the copper deposits exhibit good comprehensive mechanical properties. In addition, the surface selfnanocrystallization also makes the copper deposits show a better corrosion resistance in a neutral aqueous 0.1 M NaCl solution. This study aims to promote a convenient, controllable and reliable surface selfnanocrystallization process in electroforming for improving the global performance of deposits. Keywords
abrasive induced, corrosion resistance, electroforming, mechanical properties, surface self-nanocrystallization
1. Introduction Electroforming is a well-known manufacturing process that is a versatile bottom-up method performed on a conductive substrate for manufacturing metallic parts with complex shapes (Ref 1-4). However, grains of deposits always show an increase in size with an increase in the deposit thickness, and a coarse columnar grain layer is finally generated on top of the deposits (Ref 5-7). The coarse columnar grain layer leads to low surface strength of deposits, resulting in low global strength of deposits (Ref 8-10). Furthermore, the coarse columnar grain layer also causes low corrosion resistance of deposits. Corrosion cracks easily form on the surface and accelerate the failure of deposits (Ref 8-10). Consequently, optimizing the surface structure of deposits for improving its surface properties and global performance becomes an urgent problem to resolve. Nanocrystalline materials structurally characterized by ultrafine grains in the nanometer range exhibit ultrahigh strength, microhardness and corrosion resistance (Ref 11-13). Nanosurface strengthening technology is one of the latest technologies of industrial development in the twenty-first century (Ref 1416). It can optimize surface structure and improve surface strength by generating a surface nanocrystalline layer, resulting in a considerable improvement in the global strength of the material. Moreover, the surface nanocrystalline layer can also increase the corrosio
Data Loading...
