Effects of Y addition on microstructure and properties of Al-Zr alloys
(1. Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming,
Shanghai Jiao Tong University, Shanghai 200240, China;
2. The State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China;
3. Zhongtian Technology Corporation, Nantong 226009, China)
Shanghai Jiao Tong University, Shanghai 200240, China;
2. The State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China;
3. Zhongtian Technology Corporation, Nantong 226009, China)
Abstract: Microstructure and properties of Al-0.30Zr and Al-0.30Zr-0.08Y (mass fraction, %) alloys were investigated by electrical conductivity measurements, microhardness tests, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Micron-sized primary Al3Y phases form within grains and at grain boundaries simultaneously as product of eutectic reaction in as-cast Al-Zr-Y alloys. The addition of Y obviously accelerates the precipitation kinetics of Al3Zr (L12) in Al-Zr-Y alloys. The Al-Zr-Y alloys exhibit greater electrical conductivity during aging due to formation of increased volume fractions of Al3(Zr,Y) precipitates. In ternary Al-Zr-Y alloys, spheroidal L12-structured Al3(Zr,Y) precipitates with increased number density and smaller mean radius were observed. The Al-0.30Zr-0.08Y alloys show improved recrystallization resistance compared with Al-0.30Zr alloys
Key words: Al-Zr-Y alloy; yttrium; heat treatment; recrystallization; microstructure; mechanical property