弹性元件用铍青铜热变形行为及热处理研究

发布时间：2018-11-16 12:37

【摘要】：QBe2铍青铜是一种时效强化型合金,具有较好的弹性、塑性、强度、无磁性等优良性能,广泛应用在很多行业,被誉为“有色弹性材料之王”。根据课题要求,致力于获得一种优良性能的弹性元件,本文通过对该合金分别进行热变形行为和热处理后的性能及组织研究,分析和讨论了QBe2铍青铜的高温塑性变形行为,及热处理对QBe2铍青铜的性能及微观组织的影响。研究结果表明:流变应力随着温度的升高而降低,随着应变速率的降低而降低。在温度为600℃、640℃,应变速率为0.001 s~(-1)、0.01s~(-1)的条件下流变应力曲线总体呈现动态软化型,在热拉伸条件为600℃-0.001s~(-1)尤其明显;而在680℃-0001~0.01s~(-1)条件下,呈现为稳定流动型。在温度为600~680℃、应变速率为0.001~0.01s~(-1)的条件下,对QBe2铍青铜热变形过程综合分析,可知合金的热变形激活能Q=204.92KJ/mol,Arrhenius型本构方程为:在时效处理过程中,随着温度的升高,QBe2铍青铜的抗拉强度和伸长率均先达到一定峰值,然后下降;硬度值逐渐降低,但较热处理前原始状态,合金的硬度均增强。随着时效时间的延长,合金的抗拉强度与伸长率同样是先增大然后呈现减小的趋势。240℃/2h,空冷+400℃/4h,空冷的时效工艺下,硬态QBe2铍青铜合金的综合性能最佳,合金的抗拉强度为833MPa,弹性模量为132.4 GPa,伸长率为17.7%。分级时效后合金的综合力学性能优于常规时效,随着时效温度越高,时效时间越,长瘤状γ相增多,β相细小均匀。常规时效中低温长时间时效,高温短时间时效有利于提高合金弹性,同时分级时效中退火孪晶的出现,也有利于提高合金综合力学性能。通过对弹性性能优化的实验研究,发现弹性性能最佳的时效工艺为:硬态/780℃/15min,水淬+240℃/2h,空冷+400℃/4h,空冷。在此工艺下簧片能够保持25次弯曲90o后,具有良好弹性的性能。厚度为0.15mm,圆弧角度为110o的硬态QBe2铍青铜簧片获得的弯矩值最大,而厚度为0.3mm、圆弧角度为60o簧片获得的弯矩值最小。
[Abstract]:QBe2 beryllium bronze is a kind of aging strengthened alloy with good properties such as elasticity, plasticity, strength and nonmagnetism. It is widely used in many industries and is called "king of colored elastic materials". According to the requirements of the project, we are committed to obtain a kind of elastic element with excellent properties. In this paper, the high temperature plastic deformation behavior of QBe2 beryllium bronze is analyzed and discussed by studying the hot deformation behavior and the properties and microstructure of the alloy after heat treatment, respectively. And the effect of heat treatment on the properties and microstructure of QBe2 beryllium bronze. The results show that the flow stress decreases with the increase of temperature and with the decrease of strain rate. When the temperature is 600 鈩，

本文编号：2335536