【摘要】：當(dāng)前,錫磷青銅產(chǎn)品廣泛應(yīng)用于各種高新技術(shù)行業(yè),為了滿足不同行業(yè)的需求,對材料組織成分、表面質(zhì)量以及尺寸精度,特別是對抗拉強(qiáng)度、屈服強(qiáng)度等力學(xué)性能的要求越來越高。目前改善錫磷青銅合金性能的主要方法有：錫磷青銅摻雜鐵、鈰等稀土元素；通過電磁處理改善錫磷青銅鑄造組織；優(yōu)化錫磷青銅合金的熱處理工藝條件。本課題對錫磷青銅C5191(QSn6.5-0.1)進(jìn)行了不同熱處理工藝和冷變形處理工藝試驗,以及改變不同合金元素含量的試驗研究,利用SEM和直讀光譜儀對所得試樣進(jìn)行組織觀察分析和成份分析,并利用電子萬能材料試驗機(jī)對抗拉強(qiáng)度、屈服強(qiáng)度、硬度、延伸率等力學(xué)性能進(jìn)行了測試分析,考察了不同熱處理工藝和冷變形處理工藝,以及不同錫、磷和鎳含量對錫磷青銅C5191(QSn6.5-0.1)組織和性能的影響,結(jié)果表明：(1)錫磷青銅C5191通過230℃C、220℃、210℃、200℃低溫退火4h,隨著退火溫度下降,晶粒細(xì)化程度加大,經(jīng)200℃的低溫退火4h的合金再結(jié)晶最完全,晶粒細(xì)化程度最大；低溫退火條件下的錫磷青銅C5191屈服強(qiáng)度比沒有退火的高,隨著退火溫度的下降,合金延伸率隨之下降,屈服強(qiáng)度不斷提高,而抗拉強(qiáng)度略微減小,屈強(qiáng)比不斷提高,在200℃C熱處理4h后的合金屈強(qiáng)比提高到0.95。(2)錫磷青銅C5191通過200℃的低溫退火分別保溫2h、3h、4h、5h,合金組織在保溫4h后,組織晶粒最細(xì)小,合金的抗拉強(qiáng)度與屈服強(qiáng)度隨著退火時間的延長,先降低、后升高、再降低,而延伸率隨著退火時間的延長,先降低、后升高；在200℃退火4h,合金的屈強(qiáng)比達(dá)到最大。(3)錫磷青銅C5191合金在650℃、4h均勻化退火后進(jìn)行冷軋變形,隨著冷變形量的增加,組織中孿晶的寬度和數(shù)量都會相應(yīng)增加,試驗說明塑性變形會使合金發(fā)生滑移和孿生兩種不同變形機(jī)制,而孿生在冷軋變形后更為明顯。(4)錫磷青銅C5191合金在650℃、4h均勻化退火后進(jìn)行冷軋變形,隨冷變形量增大,合金抗彎折次數(shù)變少、伸長率變小、硬度與抗拉強(qiáng)度增大,在變形過程中溶質(zhì)原子Sn與Cu原子發(fā)生反應(yīng),使合金的層錯能下降,促進(jìn)了孿晶的形成,冷軋變形后錫磷青銅合金的強(qiáng)度和彈性極限能夠通過孿晶的形變來提高。(5)錫磷青銅C5191合金在冷變形后進(jìn)行低溫退火,合金內(nèi)部出現(xiàn)大量溶質(zhì)原子偏聚在形變孿晶區(qū)域說明了冷變形是在低溫退火之前所必須經(jīng)歷的過程,也是能夠起到強(qiáng)化作用的前提條件,不僅提供了附加能量,還于組織內(nèi)部產(chǎn)生有序疇,在退火后提高了合金的硬度與強(qiáng)度。(6)隨著Sn元素含量的增加錫磷青銅C5191合金組織未有很大變化,合金的抗拉強(qiáng)度和屈服強(qiáng)度有一定幅度的提高,屈強(qiáng)比在Sn含量高于6.08%后有小幅下降,因此錫磷青銅中Sn的含量應(yīng)該保持在6.08%左右。(7)隨著P元素含量的增加錫磷青銅C5191合金組織中晶粒的生長被逐漸抑制,但P含量高于0.14%時晶粒反而變大。合金的硬度隨P元素含量增加有小幅度提升,抗拉強(qiáng)度和屈服強(qiáng)度都是先升高后降低,屈強(qiáng)比在含量為0.14%達(dá)到最高,因此錫磷青銅中P的含量應(yīng)該保持在0.14%左右。(8)隨著Ni元素含量的增加錫磷青銅C5191合金中γ相的生長被抑制,但過高的Ni含量會導(dǎo)致組織析出硬脆相。合金的硬度隨Ni元素增加先降低后升高,抗拉強(qiáng)度與屈服強(qiáng)度都隨Ni含量的增加先升高后降低,屈強(qiáng)比在Ni含量為0.151%時達(dá)到最高,因此錫磷青銅中Ni的含量應(yīng)該保持在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，

本文編號：2361583