Effect of zirconium on microstructures and mechanical properties of squeeze cast Al–5.0Cu–0.4Mn–0.1T

• 作 者: MENG Fan-sheng ZHANG Wei-wen HU Yuan ZHANG Da-tong YANG Chao
• 机 构: National Engineering Research Center of Near-net-shape Forming for Metallic Materials, South China U
• 出 处: 中南大学学报（英文版）
• 发表日期: 2017年10期
• 关键词: Zr squeeze pressure mechanical property microstructure

Al–5.0Cu–0.4Mn alloys with different Zr additions have been prepared by direct squeeze casting. The effects of Zr on microstructures and mechanical properties of the as-cast and T6 heat-treated alloys were investigated by tensile test, optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the optimal tensile property of the as-cast alloy occurs at the Zr content of 0.15% (mass fraction) due to the Zr poisoning action and the appearance of bulky primary Al3Zr, which decreases the grain refinement strengthening effect of the as-cast alloy. The peak values of ultimate tensile strength and yield strength of the T6 alloy occur at the Zr content of 0.25%, and that of the elongation occurs at Zr content of 0.05%. This is mainly attributed to the strengthening effect of dispersed precipitation of Al3Zr and θ′ phases. The optimal mechanical properties of T6 heat-treated alloy are the tensile strength of 429 MPa, the yield strength of 327 MPa and the elongation of 18%, respectively when the squeeze pressure is 100 MPa and Zr content is 0.25%.