プロペルチ連続鋳造圧延中の導電用Al-Zr-Si-Fe合金の比抵抗とマクロ組織の変化

抄録

Measurements of resistivity, density and hardness of Al-0.35mass%Zr-0.15mass%Fe-0.10mass%Si alloys for every step of Properzi continuous casting and rolling process (PCCR) have been carried out, and macrostructures of a cast bar and a wire rod have been observed. The low resistivity portion due to precipitation of alloying elements or impurities is found at the core of cast bar. Columnar structure of copper mold side in a cast bar similarly survives after rolling to 9.7mm diameter wire rod. Resistivity increment by rolling in the process is about 1.2nΩm, which should be an overestimation due to crack around intermetallic compound. At the core of rolled wire rod, hard portion is formed by some precipitation during the rolling. Filtrate analysis after hot phenol dissolution for wire rods containing 0.05-0.15mass%Si shows that Fe of 160-200ppm is in solution. Resistivity measurements for these wire rods indicates that Zr of 0.19-0.26mass% is in solution, and amount of precipitated Zr during solidification or in solid state increases with increasing amount of Si addition.