Copper Deposits with High Tensile Strength and Elongation Electroformed in an Ultra-Low-Concentration Sulfate Bath witho
- PDF / 1,481,238 Bytes
- 6 Pages / 593.972 x 792 pts Page_size
- 102 Downloads / 217 Views
JMEPEG DOI: 10.1007/s11665-016-2494-5
Copper Deposits with High Tensile Strength and Elongation Electroformed in an Ultra-Low-Concentration Sulfate Bath without Additives Chunjian Shen, Zengwei Zhu, Di Zhu, and Jianhua Ren (Submitted July 7, 2016; in revised form October 24, 2016) Superior mechanical properties of copper are needed in industries to meet high application requirement. In this study, an electroformed copper with superior mechanical properties is achieved by using a simple ultralow-concentration copper sulfate bath containing neither chloride nor organic additives. Copper deposits obtained in the copper sulfate concentrations ranging from 30 to 60 g/L exhibit high tensile strength and elongation simultaneously. A maximum tensile strength of 256 MPa is achieved, with an elongation ratio of 31%, at a copper sulfate concentration of 30 g/L, while a maximum elongation ratio of 43% is achieved, with a tensile strength of 216 MPa, at a concentration of 50 g/L. It has been found that the copper sulfate concentration affected the hydrogen content, grain arrangement and orientation index of copper deposits which determine their mechanical properties. When the copper sulfate concentration is less than 30 g/L, the excessive hydrogen content of the deposits thus produced leads to poor compactness and inferior mechanical properties. At concentrations over 50 g/L, a disordered arrangement of grains and a significant increase in the peak of (111) lead to an increase in the tensile strength but a decrease in the elongation ratio. This approach provides an effective and economical method for the copper deposits achieving superior mechanical properties. Keywords
copper deposits, electroforming, mechanical properties, ultra-low-concentration
1. Introduction Copper has high electrical and thermal conductivities and high ductility, and these properties have led to its widespread use in a number of industries, including electronics, MEMS and instrument manufacture. Electroforming is a metal forming process using electrodeposition, and it has attracted much attention in recent years for its high replication precision. Copper is one of the main metals that can be used in electroforming. So copper electroforming has been employed to prepare lots of precision parts, such as battery electrodes, sensors, contacts, the gear of micro motor and so on. With continuous increasing requirements regarding application of copper, superior mechanical properties are needed for improving reliability and prolonging the service life of copper parts. So how to improve the tensile strength and elongation of copper deposits simultaneously becomes an attractive task and a research hotspot in industries (Ref 1-5). In the conventional preparation method of electroformed copper in an acid sulfate bath, whose copper sulfate concenChunjian Shen and Jianhua Ren, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China; and Zengwei Zhu and Di Zhu, College of Mechanical and Electrical Engi
Data Loading...
