Tensile Properties and Fracture Characteristics of Nanostructured Copper and Cu-SiC Nanocomposite Produced by Mechanical
- PDF / 2,227,219 Bytes
- 8 Pages / 593.972 x 792 pts Page_size
- 85 Downloads / 194 Views
JMEPEG https://doi.org/10.1007/s11665-018-3267-0
Tensile Properties and Fracture Characteristics of Nanostructured Copper and Cu-SiC Nanocomposite Produced by Mechanical Milling and Spark Plasma Sintering Process M.R. Akbarpour (Submitted September 27, 2017; in revised form February 25, 2018) The presence of large grains within nanometric and ultrafine grain matrix is an effective method in order to enhance strength while keeping the high ductility of metals. For this purpose, in this research, spark plasma sintering (SPS) was used to consolidate milled Cu and Cu-SiC powders. In SPS process, local sparks with high temperature between particles take place and locally lead to intense grain growth, and therefore, this method has the ability to produce bimodal grain structures in copper and copper-based composites. Microstructural and mechanical studies showed 185 and 437 nm matrix grain sizes, high tensile yield strength values of 188.4 and 296.9 MPa, and fracture strain values of 15.1 and 6.7% for sintered Cu and Cu-4 vol.% SiC nanocomposite materials, respectively. The presence of nanoparticles promoted the occurrence of static recrystallization and decreased the fraction of coarse grains in microstructure. The high tensile properties of the produced materials are attributed to fine grain size, homogenous dispersion of nanoparticles and retarded grain boundary migration during sintering. Keywords
composites, mechanical, metallic matrix, nonferrous metals, powder metallurgy, sintering, static
1. Introduction Recently, the unique engineering properties of copper matrix composites have made them outstanding materials of choice for structural applications and thermal management compared to many other materials. Cu reinforced with various phases such as ceramic particles (TiC, Al2O3, etc.), intermetallic materials and carbon allotropes has been produced for different objectives such as: increase in yield strength and fatigue strength, improvement in corrosion resistance, reduction in thermal elongation and improvement in tribological properties. Several researches have shown that the reinforcing of copper with nanomaterials can considerably enhance the mechanical properties (Ref 1-4). Among Cu matrix nanocomposite, Cu-nanoSiC nanocomposites have attracted much attention in recent years because of their excellent electrical and thermal conductivity, enhanced hardness, wear resistance and frictional properties for application in welding electrodes, electrical contacts, contactors, switches, and circuit breaks (Ref 5, 6). Several techniques have been employed to sinter mechanically milled SiC-reinforced Cu matrix composites due to high hardness of high-energy mechanically milled powders and formation of metal oxides on the surface of particles which creates problems during consolidation and sintering of the
M.R. Akbarpour, Department of Materials Engineering, Faculty of Engineering, University of Maragheh, P.O. Box 55136-553, Maragheh, Iran. Contact e-mails: [email protected] and Akbarpour@ maragheh.ac.ir.
Data Loading...
