Control of Reaction Compounds at Carbon Fiber/Molten Metal Interface by Si Contents in Al-Si Alloys

Abstract

  The wettability behavior of molten Al-Si alloy and carbon fibers (CF) was evaluated by the dipping coverage method. This study focused on the effects of silicon content in Al-Si alloy melts on the wettability at 1000℃, and identified the interfacial products around the CF hot-dipped in the Al-Si alloy melts. Depending on the Si content, the interfacial product changed from Al₄C₃ to SiC. The product at the Al alloy/CF interface was Al₄C₃ when the amount of Si in the molten Al was 0 to 10 mol%. When the amount of Si was 20 mol%, it was a mixture of SiC and Al₄C₃, which is different from the prediction based on the calculated phase diagram. This was due to a partial decrease in the concentration of silicon in the Al-Si alloy during SiC formation. The change trend of the wetting rate with Si content was almost consistent with that of the driving force for carbide formation. This suggests that the change in wetting rate with Si content may be due to the difference in the formation rate of interfacial products.