Porous NiCu alloy with tailored pore structure and mechanical property fabricated by freezing casting

Abstract

Porous NiCu alloys with tailored pore structure were successfully produced by freezing casting method using Ni and Cu powders as raw materials. The pores are elongated, and the porosity, wall thickness and pore width can be controlled by the solid content of the slurry and freezing temperature. The structures and mechanical properties of the porous NiCu alloys were investigated. Results show that as the solid content increases from 5% to 20 wt %, the porosity and pore width of porous NiCu alloys decrease, while the wall thickness increases. The porosity nearly keeps constant with the same solid content but different freezing temperature. The compressive strength rises with the increasing solid content due to the deceased porosity under the same strain. The 0.2% yield strength has a good linear relationship with the porosity, and drops from 12.6 MPa to 2.9 MPa when the porosity rises from ~64% to ~85% with corresponding solid content decreases from 20 to 5%.