Effect of volume fraction on properties of a glass microballoon/Al-12%Si alloy composite

Abstract

A low density composite (Shirasu Balloons Aluminum Composite: SBAC) of volcano glass microballoons (Shirasu Balloons: SB) and aluminum alloy (Al-12%Si) was investigated in terms of the effect of volume fraction (V_SB) of SB on tensile strength (σ_T), compressive strength (σ_C), shear modulus (G), internal friction coefficient (Q^-1) and specific conductivity (C) of SBAC. The value of G decreased exponentially and monotonously with the increase in V_SB and showed good agreement with logarithmic mixture rule. The values of σ_T, σ_C and C also decreased exponentially with the increase in V_SB, but their curves inflected sharply toward low values at about 50vol% of SB. On the other hand, Q^-1 value increased linearly with the increase in V_SB and the curve inflected sharply toward high value at about 50vol% of SB. The V_SB of their knee points (about 50vol%) seemed to be the volume fraction above which contact points of SB in SBAC markedly increased.