基于微观组织特征的航天铝铜合金力学行为研究

航天大型铝合金构件"一体化制造"随着商业航天迅速发展而得到日益广泛的应用,制造流程中铸造形成的微孔洞、偏析及晶粒尺寸等微观组织特征,对工艺及服役过程中材料力学行为的影响至关重要,是理解与预测构件复杂变形规律的基础。针对铝铜合金铸造-热处理的制造流程,定量表征了铸造微孔洞、成分、析出物等典型微观组织特征的分布规律,进一步建立了淬火析出相、微孔洞、成分偏析等对延伸率、屈服强度、流动应力等力学行为的影响模型。研究表明,微孔洞及合金偏析对淬火与时效后的力学性能有着不可忽略的影响。研究深化了制造过程铝合金力学性能形成的理解,是基于微观组织特征的本构模型的建立基础,并将为航天铝合金大型构件一体化制造提供理论支持与技术指导。

In recent years, the increasing demand on the international commercial launching has been promoting the development of integrative manufacturing. The deformation control of the structures becomes one of the main problems about the quality control. The porosity, segregation and grain size and other microstructural characteristics in casting have a crucial influence on mechanical behavior of materials in integrative manufacturing processes for aerospace Al-Cu alloys. Understanding the relation between casting defects and mechanical properties is the base to formulate and predict the complicated structural deformation. The distribution of the porosity, chemical composition, and precipitates is quantitatively characterized for the ongoing through-process research. The models are investigated to present the effects of the quench-induced precipitates, porosity and segregation on elongation, yield strength, flow stress, etc. The research deepens the understanding on the evolution of mechanical properties of Al-Cu alloy, which is the base to establish the microstructural characteristics-based constitutive model. It will provide theoretical support and technical guidance for the integrative manufacturing of large aerospace structures.