Characterization of electrical conductivity of porous metal fiber sintered sheet using four-point probe method

Novel porous metal fiber sintered sheets (PMFSSs) with different porosities were fabricated by sintering copper fibers. Using four-point probe method, comparative study was conducted to investigate the effects of probe spacing, porosity, and sintering condition on the electrical conductivity of PMFSS. Our experimental results showed that probe spacing plays an important role in determining the electrical conductivity. Uniform probe spacing was adopted in order to reduce the error caused by non-uniformity of probe spacing. The measured electrical conductivity was found to decrease with increasing porosity ranging from 70% to 90% for the PMFSS produced under the same sintering condition. Our experimental results were found to agree well with the theoretical prediction by Liu’s model for the PMFSS with different porosities. The effect of sintering condition on electrical conductivity was also investigated. It was revealed that higher sintering temperature or longer holding time yields higher electrical conductivity of PMFSS.