Field-assisted solid phase sintering of W-20 wt.% Cu nanocomposites prepared by co-precipitation method

W-20 wt.% Cu composite powders were synthesized by co-precipitation combined with subsequent hydrogen reduction method. The composite powders with fine size and homogenously distributed phases exhibit strawberry-like morphology where scattered W nanoparticles stuck to the surface of Cu particles. Regardless of the low content of Cu, the as-synthesized powders could be rapidly densified at solid state by using the field assisted sintering technique (FAST), which was benefited from the high sinterability of the initial powders prepared by co-precipitation and the unique sintering mechanism of FAST, i.e., the combination of mechanical, thermal and current effects on the sintering process. Both sintering temperature and pressure show significant influence on the relative density and elemental distribution of the final W-Cu composites. A maximum relative density of 96.7% was achieved from the samples sintered at 970 degrees C under 120 MPa in which W and Cu are uniformly distributed. Correspondingly, the composites show excellent thermal conductivity and low coefficient of thermal expansion (CTE), making them candidate materials for high density electronic packaging.