Microwave-assisted synthesis of Cu–ZrB₂ MM Nano-composite using double pressing double sintering method

In this research work, copper (Cu)–ZrB₂ nano-composites were synthesized with different weight percentages of ZrB₂ by double pressing double sintering method. The nano size of ZrB₂ were distributed in the powder Cu by ball milling with ZrO₂ balls in which the size of ZrB₂ is < 20 nanometers and the amount of ZrB₂ particles varies between 0 and 12% of the mixture. Particles were fully distributed and pressed, and the pressed pellets were sintered both, in an Ar atmosphere of tube furnace at 650 °C and microwave oven. Microwave sintering process allows us to reduce the sintering time by 16 min. Study on the nano-composite microstructures showed that the reinforcing particles were uniformly distributed in the matrix. The Cu–ZrB₂ nano-composite samples were characterized using micro-hardness, X-ray diffraction analysis, scanning electron microcopy, abrasion, compressive strength and flexural strength tests. An increase in the percentage of ZrB₂ nanoparticle led to an improvement in the mechanical properties of the product. The optimum amount of the reinforcing ZrB₂ was determined to be 10% of the mixture.