Thermal stability and properties of Cu-TiB2 nanocomposites prepared by combustion synthesis and spark-plasma sintering

In the present work, Cu-TiB2 nanocomposite powders were synthesized by combining high-energy ball-milling of Cu-Ti-B mixtures and subsequent self-propagating high temperature synthesis (SHS). Cu-40wt.%TiB2 powders were produced by SHS reaction and ball-milled. The milled SHS powder was mixed with Cu powders by ball milling to produce Cu-2.5wt.%TiB2 composites. TiB2 particles less than 250nm were formed in the copper matrix after SHS-reaction. The releative density, electrical conductivity and hardness of specimens sintered at 650-750 degrees C were nearly 98%, 83%IACS and 71H(R)B, respectively. After heat treatment at 850 to 950 degrees C for 2 hours under Ar atmosphere, hardness was descedned by 15%. Our Cu-TiB2 composite showed good thermal stability at eleveated temperature.