航天贮箱用典型规格2219铝合金板材不同热处理状态下的性能研究

Research on performance of typical specification 2219 aluminum alloy sheet under different heat treatment conditions for rocket tank

为提高新一代运载火箭的有效载荷、提升可靠性,贮箱对材料性能及匹配的成形工艺有更高的要求。以运载火箭贮箱用典型规格(厚度为6 mm)的2219铝合金板材为研究对象,通过研究不同轧制方向、热处理状态下的基本力学性能,建立热处理状态对基本力学性能的影响曲线,形成表征2219铝合金在不同热处理状态下的弹塑性参数。结果表明:轧制方向对不同热处理状态的2219铝合金力学性能的影响不同,在退火态下,平行于轧制方向的强度较高;而在固溶温度为535℃下保温30 min后的淬火态下,垂直于轧制方向的性能较高,淬火后的板材均匀塑性变形能力得到了提高,抗拉强度及应变硬化指数是退火态的2倍以上,屈服强度、伸长率及各向异性系数比退火态板材略有提高,优化成形工艺窗口,实现淬火态成形,有效地规避热处理变形。

s In order to improve the payload and the reliability of new generation launch vehicles,the rocket tank has higher requirements for material properties and matching forming processes.For the typical specification 2219 aluminum alloy sheet with the thickness of 6 mm used in the rocket tank,the influence curves of heat treatment state on the basic mechanical properties were established by studying on the basic mechanical properties under different rolling directions and heat treatment conditions,and the elastoplastic parameters of 2219 aluminum alloy under different heat treatment conditions were characterized.The results show that the rolling directions have different effects on the mechanical properties of 2219 aluminum alloy under different heat treatment conditions,and the strength parallel to the rolling direction in the annealed state is higher.However,after holding for 30 min at solution temperature of 535℃,the performance perpendicular to the rolling direction in the quenched state is higher.Furthermore,the uniform plastic deformation capacity of quenched sheet is improved,and the tensile strength and strain hardening exponent reach more than two times of the annealed state.At the same time,the yield strength,elongation and anisotropy coefficient are slightly improved compared with the annealed sheet,and the window of forming process is optimized to achieve forming in the quenched state and effectively avoid the deformation of heat treatment.