Microstructure and mechanical properties of novel Al-Y-Sc alloys with high thermal stability and electrical conductivity

• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2020,（1）
• 页码范围: 1-6
• 页数: 6页
• 语种: 英文

摘要

The microstructure and mechanical properties of novel Al-Y-Sc alloys with high thermal stability and electrical conductivity were investigated.Eutectic Al3Y-phase particles of size 100-200 nm were detected in the as-cast microstructure of the alloys.Al3Y-phase particles provided a higher hardness to as cast alloys than homogenized alloys in the temperature range of 370-440 ℃.L12 precipitates of the Al3(ScxYy) phase were nucleated homogenously within the aluminium matrix and heterogeneously on the dislocations during annealing at 400 ℃.The average size of the L12 precipitates was 11 ±2 nm after annea ling for 1 h,and 25-30 nm after annealing for 5 h,which led to a decrease in the hardness of the Al-0.2Y-0.2Sc alloy to 15 HV.The recrystallization temperature exceeded 350 ℃ and 450 ℃ for the Al-0.2Y-0.05Sc and Al-0.2Y0.2Sc alloys,respectively.The investigated alloys demonstrated good thermal stability of the hardness and tensile properties after annealing the rolled alloys at 200 and 300 ℃,due to fixing of the dislocations and grain boundaries by L12 precipitates and eutectic Al3Y-phase particles.The good combination of strength,plasticity,and electrical conductivity of the investigated Al-0.2Y-0.2Sc alloys make it a promising candidate for electrical conductors.The alloys exhibited a yield stress of 177-183 MPa,ultimate tensile stress of 199-202 MPa,elongation of 15.2-15.8％,and electrical conductivity of 60.8％-61.5％ IACS.