Dissolution Sintering Technique to Create Porous Copper with Sodium Chloride Using Polyvinyl Alcohol Solution through Powder Metallurgy

Abstract

The main purpose of this paper was to investigate the relative densities, porosities, compression strength and energy absorbed by porous copper (Cu) formed via the dissolution sintering technique using Polyvinyl Alcohol (PVA) solution as a binder with Sodium Chloride (NaCl) as space holder. Porous Cu was fabricated through powder metallurgy route using dissolution sintering technique by mixing Cu with NaCl in the volume ratio of 1:1, 1:2, 1:3 and 1:4 and adding PVA solution as binder. The mixture was poured into a press die of 1inch internal diameter and a pressure of 375MPa was applied by a 4 column hydraulic press to create the green form. The NaCl was leached out in hot water at 70°C and then sintered to a temperature of 850°C. Porosity values were determined from density measurements to give the porosity values of 42.2, 44.87, 45.71 and 57.79% for volume ratio of 1:1, 1:2, 1:3, 1:4 respectively. Compression tests were also performed. The results of various plots were used in determining the energy absorbed per unit volume of value of 9.637 MJ/m³, 0.750 MJ/m³, 0.167 MJ/m³, 0.109 MJ/m³ and the compressive strength of 40 MPa, 3.75, 0.72 MPa, 0.26 MPa for volume ratio of 1:1, 1:2, 1:3 and 1:4 respectively. Scanning Electron Microscope (SEM) was used to characterize the morphology of the pure Cu, the NaCl and the resulting porous Cu.