Spark plasma sintering of silver nanopowder

摘要

The spark plasma sintering behaviour of silver nanopowder prepared by the electro-explosion method was investigated. Consolidation was carried out from 50℃ to 800℃ for 5 mins at 34 MPa with differential scanning calorimetry indicating a sintering onset temperature as low as 160℃ and an activation energy of 86+1 kJ/mol. Near full density resulted from treatment at 300℃, and at higher temperatures a normal Hall-Petch relation is obeyed. The enhancement of Vicker's hardness to 1000MPa for materials sintered at 300℃ is three times greater than for silver annealed in a conventional way. While polysynthetic twinning contributes to superior hardness, the primary cause is the sub-micron grain size.