Enhancing strength and electrical conductivity of pure aluminum by microalloying with telluride

Abstract

The effects of Te addition on the microstructure, strength and electrical conductivity of pure aluminum were investigated, for improving the strength and electrical conductivity of resulting alloys. It was found that the tensile strength and electrical conductivity of the studied alloys increased by 25.8% and 2.8%, respectively, compared with those for pure aluminum (58 MPa and 62.06% IACS), respectively, by adding 0.1 wt% Te. Several mechanisms may account for the observed improvement of the alloys’ strength and electrical conductivity. First, Te addition can refine the grain size of pure aluminum by introducing more nucleation sites and suppressing grain growth through boundary precipitation. Second, the precipitation morphology changes from fine-needle or sheet-like to ellipsoidal shapes, likely improving the alloys’ tensile properties. Finally, Te can purify the melts by forming Al-Te-Fe-Si intermetallics at the grain boundaries, likely reducing the lattice distortion and increasing the electrical conductivity.

Keywords

• Al-Te alloys
• grain refinement
• Al-Te-Fe-Si intermetallics
• mechanical property
• electrical conductivity