应用于某型号航天卫星的ZL114A支架铸件选用开放式浇注系统,结合不同铸型材料与结构设计,在低压充型下实现了自下而上与自内向外的顺序凝固,铸型温度呈现出先上升后下降的变化趋势.聚乙二醇65℃下淬火可有效缩短薄膜传热时间,提高淬火冷却速度且降低淬火热处理变形,T6热处理后在-120℃液氮下保温2 h后,本体剖切试样平均抗拉强度、屈服强度、伸长率与布氏硬度分别为336 MPa、281 MPa、5.8%与87.5.初生α-Al基体铸态晶粒尺寸约为86μm,铸态沿晶界分布的初生与共晶Si相呈现为板片状与短棒状,经T6热处理后,Si相形貌转变为球状,断裂机制由沿晶断裂转变为韧窝断裂.%With the choosing of open filling system and design of different mold materials and structure, the ZL114A stent casting used in a space satellite attains a solidification order from bottom to up and from inside to outside under the low-pressure filling process, the temperature of mold shows a tendency from rise to decrease. The quenching deformation and film heat transfer reduce when the temperature of polyethylene glycol is 65℃;the average tensile strength, yield strength, elongation and Brinell hardness of the T6 heat treatment after cryogenic treatment are 336 MPa, 281 MPa, 5.8% and 87.5. The grain size of primary aluminum matrix is 86μm, and the primary and eutectic Si phase that shows a plate-like and short rod shape distributes nearby the grain boundaries, the Si phase morphology changes into spherical and the fracture mechanism transforms from intergranular to dimple after the T6 heat treatment.
展开▼
