锡磷青铜（C5191）合金组织与性能研究

发布时间：2018-11-27 17:45

【摘要】：当前,锡磷青铜产品广泛应用于各种高新技术行业,为了满足不同行业的需求,对材料组织成分、表面质量以及尺寸精度,特别是对抗拉强度、屈服强度等力学性能的要求越来越高。目前改善锡磷青铜合金性能的主要方法有：锡磷青铜掺杂铁、铈等稀土元素；通过电磁处理改善锡磷青铜铸造组织；优化锡磷青铜合金的热处理工艺条件。本课题对锡磷青铜C5191(QSn6.5-0.1)进行了不同热处理工艺和冷变形处理工艺试验,以及改变不同合金元素含量的试验研究,利用SEM和直读光谱仪对所得试样进行组织观察分析和成份分析,并利用电子万能材料试验机对抗拉强度、屈服强度、硬度、延伸率等力学性能进行了测试分析,考察了不同热处理工艺和冷变形处理工艺,以及不同锡、磷和镍含量对锡磷青铜C5191(QSn6.5-0.1)组织和性能的影响,结果表明：(1)锡磷青铜C5191通过230℃C、220℃、210℃、200℃低温退火4h,随着退火温度下降,晶粒细化程度加大,经200℃的低温退火4h的合金再结晶最完全,晶粒细化程度最大；低温退火条件下的锡磷青铜C5191屈服强度比没有退火的高,随着退火温度的下降,合金延伸率随之下降,屈服强度不断提高,而抗拉强度略微减小,屈强比不断提高,在200℃C热处理4h后的合金屈强比提高到0.95。(2)锡磷青铜C5191通过200℃的低温退火分别保温2h、3h、4h、5h,合金组织在保温4h后,组织晶粒最细小,合金的抗拉强度与屈服强度随着退火时间的延长,先降低、后升高、再降低,而延伸率随着退火时间的延长,先降低、后升高；在200℃退火4h,合金的屈强比达到最大。(3)锡磷青铜C5191合金在650℃、4h均匀化退火后进行冷轧变形,随着冷变形量的增加,组织中孪晶的宽度和数量都会相应增加,试验说明塑性变形会使合金发生滑移和孪生两种不同变形机制,而孪生在冷轧变形后更为明显。(4)锡磷青铜C5191合金在650℃、4h均匀化退火后进行冷轧变形,随冷变形量增大,合金抗弯折次数变少、伸长率变小、硬度与抗拉强度增大,在变形过程中溶质原子Sn与Cu原子发生反应,使合金的层错能下降,促进了孪晶的形成,冷轧变形后锡磷青铜合金的强度和弹性极限能够通过孪晶的形变来提高。(5)锡磷青铜C5191合金在冷变形后进行低温退火,合金内部出现大量溶质原子偏聚在形变孪晶区域说明了冷变形是在低温退火之前所必须经历的过程,也是能够起到强化作用的前提条件,不仅提供了附加能量,还于组织内部产生有序畴,在退火后提高了合金的硬度与强度。(6)随着Sn元素含量的增加锡磷青铜C5191合金组织未有很大变化,合金的抗拉强度和屈服强度有一定幅度的提高,屈强比在Sn含量高于6.08%后有小幅下降,因此锡磷青铜中Sn的含量应该保持在6.08%左右。(7)随着P元素含量的增加锡磷青铜C5191合金组织中晶粒的生长被逐渐抑制,但P含量高于0.14%时晶粒反而变大。合金的硬度随P元素含量增加有小幅度提升,抗拉强度和屈服强度都是先升高后降低,屈强比在含量为0.14%达到最高,因此锡磷青铜中P的含量应该保持在0.14%左右。(8)随着Ni元素含量的增加锡磷青铜C5191合金中γ相的生长被抑制,但过高的Ni含量会导致组织析出硬脆相。合金的硬度随Ni元素增加先降低后升高,抗拉强度与屈服强度都随Ni含量的增加先升高后降低,屈强比在Ni含量为0.151%时达到最高,因此锡磷青铜中Ni的含量应该保持在0.151%左右。
[Abstract]:At present, the tin-phosphor bronze products are widely used in various high-tech industries. In order to meet the needs of different industries, the requirements of the components, surface quality and dimensional accuracy of the materials, in particular the mechanical properties such as tensile strength and yield strength, are higher and higher. The main methods for improving the properties of the tin-phosphorus bronze alloy are as follows: the rare-earth elements such as tin-phosphor bronze-doped iron, iron and the like are improved; the tin-phosphorus bronze casting structure is improved by the electromagnetic treatment; and the heat treatment process conditions of the tin-phosphorus bronze alloy are optimized. In this paper, the process of different heat treatment and cold deformation treatment of the tin-phosphor bronze C5191 (QSn6.5-0.1) and the experimental study on the content of different alloy elements were studied. The samples were analyzed and analyzed by means of SEM and direct-reading spectrometer. The mechanical properties of the tensile strength, the yield strength, the hardness and the elongation were tested and analyzed by using the electronic universal material testing machine. The effects of different heat treatment process and cold deformation treatment process, and the microstructure and properties of the tin-phosphor bronze C5191 (QSn6.5-0.1) with different tin, phosphorus and nickel content were investigated. The results show that: (1) The tin-phosphorus bronze C5191 is annealed at 230 鈩，

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