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分析了铸态和挤压态ZK60 xGd(x=0~4)合金的组织和相组成,测试了其拉伸力学性能。结果表明,随着Gd含量的增加,铸态组织逐渐细化,Mg Zn Gd新相逐渐增多,而MgZn2相逐渐减少直至消失,第二相趋于连续网状分布于晶界处;当Gd含量不超过2.98%时,铸态室温拉伸力学性能稍降低。经挤压比=40和挤压温度T=593 K的挤压后,组织显著细化,平均晶粒尺寸逐渐减至ZK60 2.98Gd合金的2μm,破碎的第二相沿着挤压方向呈带状分布;挤压态的拉伸力学性能均显著提高:298和473 K时的抗拉强度分别从ZK60合金的355和120MPa逐渐提高至ZK60 2.98Gd合金的380和164 MPa。挤压态拉伸断口呈现典型的韧性断裂特征。
The microstructures and phase compositions of ZK60 xGd (x = 0 ~ 4) alloy in as-cast and extruded state were analyzed and their tensile properties were tested. The results show that with the increase of Gd content, the as-cast microstructure is refined and the new phase of Mg Zn Gd is gradually increased while the MgZn2 phase is gradually reduced until it disappears, while the second phase tends to be continuously reticulate distributed at the grain boundary. When the ratio is not more than 2.98%, tensile mechanical properties of as-cast at room temperature slightly decrease. After the extrusion ratio = 40 and extrusion temperature T = 593 K extrusion, the organization significantly refined, the average grain size gradually reduced to ZK60 2.98Gd alloy 2μm, broken second phase along the extrusion direction strip Tensile strength at 298 and 473 K increased from 355 and 120 MPa for ZK60 alloy to 380 and 164 MPa for ZK60 2.98Gd alloy, respectively. Extruded tensile fracture shows a typical ductile fracture characteristics.