Mechanical behavior of TiB_2 Nanoparticles Reinforced Cu Matrix Composites Synthesized by In-Situ Processing

摘要

Cu-TiB_2 nanocomposite powders were in situ synthesized by combining high-energy ball milling of Cu-Ti-B elemental powder mixtures as precursors and subsequent self-propagating high temperature synthesis (SHS). Cu-40wt.% TiB_2 was produced after SHS reaction and then diluted by copper to obtain desired homogeneous composites with 2.5, 5 and 10wt.%TiB_2. Spark plasma sintering (SPS) was used to inhibit grain growth and thereby obtain fully Cu-TiB_2 sintered bodies with nanocomposite structure. After SHS reaction, only Cu and TiB_2 phases were detected in the SHS-product. Spheroidal TiB_2 particles smaller than 250nm were formed in the copper matrix after SHS-reaction. Mechanical and electrical properties were investigated after SPS at 650°C for 30min under 50MPa. The electrical conductivity decreased from 75 to 54% IACS with increasing of TiB_2 contents from 2.5 to 10wt.%. However, hardness increased from 56 to 97HrB. In addition, the tensile strength increased with increasing the TiB_2 content.