ZL205A上臂铸件低压充型工艺设计

Design of Low Pressure Filling Process for ZL205A Upper Arm Casting

ZL205A属于高强韧铝铜系合金材料,经T6处理后可作为中等载荷承力部件用于航空航天等军工装备领域。文中针对ZL205A上臂铸件设计了四种不同的低压充型凝固成形工艺,选用1:1.8:4.4浇道截面比低压充型浇注系统,结合20 mm/s与40 mm/s的升液与充型速度、25 kPa与30 kPa的升液与充型压力,实现了ZL205A上臂铸件自下而上的平稳充型与自上而下的顺序凝固。T6态本体剖切试样的平均抗拉强度、屈服强度与伸长率分别为484 MPa、354.5 MPa与6.9%,经时效热处理后大量Al_2Cu与Al_6Mn沉淀强化相沿晶界均匀弥散析出,T6态断口以韧窝断裂为主,附带一定数量的沿晶断裂带。

The ZL205A alloy is a high strength and tough aluminum-copper material, which can be used as medium load bearing parts for aerospace and other military equipment field after the T6 heat treatment. In this paper, four different low-pressure solidification forming processes of ZL205A upper arm casting are designed, the runner cross-section area ratio is selected to 1：1.8：4.4, combining with the 20 mm/s and 40 mm/s of liquid rise and filling speed, together with 25 kPa and 30 kPa of liquid rise and filling pressure, an order filling sequence from bottom to top and solidification process from top to bottom are achieved. The average tensile strength, yield strength and elongation of T6 bulk specimen are 484 MPa, 354.5 MPa and 6.9% respectively, lots of A1ECU and A16Mn precipitate strengthening phases distribute nearby the grain boundaries diffusely after the aging process. The dimple rupture appears as the main fracture mechanism, accompanying with some intergranular fracture zone.