Effect of Ta content and sintering temperature on characteristics of nanocrystalline Cu-Ta nanocomposite

Abstract

In this study, the microstructural, physical and mechanical properties of the nanocrystalline Cu-Ta material synthesized by mechanical milling and subsequent sintering were investigated affected by Ta content and sintering temperature. Scanning electron microscope and X-ray diffraction results showed that increasing Ta content from 1 to 5 wt% changed the material behavior during milling and resulted in reduction of powder particle size and crystallite size. For the sintered specimens, addition of Ta decreased the electrical conductivity due to reduced density and increased electron scattering effect while micro-hardness of Cu matrix was promoted. The higher sintering temperature about 850 °C also increased density and provided more segregation of Ta which was led to improvement in both micro-hardness and electrical conductivity of Cu-Ta composite. In addition, a comparison between sintering process at 850 °C by SPS method and conventional cold pressing- sintering revealed that SPS has a high potential to enhance physical and mechanical properties.