Dense Nanostructured Nickel Produced by SPS from Mechanically Activated Powders: Enhancement of Mechanical Properties

Abstract EN

An investigation was performed to evaluate the potential of the spark plasma sintering process in producing dense nanostructured materials.

Microstructured and nanostructured nickel was sintered by SPS starting from nickel powder (APS 3–7 μm) in the as-received state and after a mechanical activation using a high-energy ball mill.

First, a sintering study to determine SPS processing conditions to reach full densification was carried out with specimens 50 mm in diameter and 10 mm in height.

In a second step, an experimental investigation was undertaken with dense nickel disks to generate tensile properties.

The tensile tests were performed at a strain rate of 10−3 s−1 with specimens 16 mm in gage length and 4 mm in gage diameter.

Tensile ductility in excess of 40% was reached with the microstructured nickel.

For the nanostructured nickel, high yield stresses in excess of 600 MPa were measured with a tensile ductility of 30%.

These results were analyzed through densification and microstructure measurements.