Mechanical properties of electroformed copper layers with gradient microstructure

• Published in: International journal of minerals, metallurgy and materials metallurgy and materials, 2010-02, Vol.17 (1), p.69-74
• Main Authors: Liao, Qiang, Zhu, Li-qun, Liu, Hui-cong, Li, Wei-ping
• Format: Article
• Language: English
• Subjects: Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Copper; COPPER (PURE); COPPER RESOURCES; Corrosion and Coatings; Crystals; Ductility; ELECTROFORMING; Electron microscopes; Glass; Grain size; HARDNESS; Materials Science; MECHANICAL PROPERTIES; Metallic Materials; Metallurgy; Microhardness; Microstructure; MICROSTRUCTURES; Natural Materials; Optical microscopes; PREFERRED ORIENTATION; PROPERTIES; SCANNING ELECTRON MICROSCOPY; Substrates; Surfaces and Interfaces; Tensile strength; Thickness; Thin Films; Tribology; Ultrasonic methods; X-ray diffraction; X射线衍射仪; 力学性能; 扫描电子显微镜; 机械性能; 梯度结构; 超声波技术
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-010-0112-3

The electroformed copper layer with gradient microstructure was prepared using the ultrasonic technique. The microstructure of the electroformed copper layer was observed by using an optical microscope （OM） and a scanning electron microscope （SEM）. The preferred orientations of the layer were characterized by X-ray diffraction （XRD）. The mechanical properties were evaluated with a Vicker＇s hardness tester and a tensile tester. It is found the gradient microstructure consists of two main parts： the outer part （faraway substrate） with columnar crystals and the inner part （nearby substrate） with equiaxed grains. The Cu-（220） preferred orientation increases with the increasing thickness of the copper layer. The test results show that the microhardness of the electroformed copper layer decreases with increasing grain size along the growth direction and presents a gradient distribution. The tensile strength of the outer part of the electroformed copper layer is higher than that of the inner part but at the cost of ductility. Meanwhile, the integral mechanical properties of the electroformed copper with gradient microstrucmre are significantly improved in comparison with the pure copper deposit.