發(fā)布時間：2018-02-25 17:50

  本文關(guān)鍵詞： 導(dǎo)電鋁合金 時效制度 電導(dǎo)率 析出相 Cu含量　出處：《山東大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：Al-Mg-Si(Cu)合金具有良好的性能如密度低、強度高、良好的延展性等機械性能以及較高的電導(dǎo)率,因此在強度和導(dǎo)電率都有要求的領(lǐng)域,例如軌道交通用的導(dǎo)電軌等獲得了廣泛的應(yīng)用。Al-Mg-Si(Cu)合金是可熱處理強化的合金,合金的強度主要取決于過飽和A1基體時析出共格或半共格納米析出相,而合金的導(dǎo)電性則是受固溶元素的數(shù)量控制的。在典型的6系列鋁合金時效過程中,強度是先升后降,而導(dǎo)電率則是持續(xù)上升的。這就造成了強度和導(dǎo)電性能之間的矛盾,目前供貨狀態(tài)的導(dǎo)電軌是處于過時效狀態(tài)來滿足導(dǎo)電率的要求。合金成分和時效制度決定著Al-Mg-Si(Cu)合金中析出物的種類數(shù)量,不但影響著強度,還影響著導(dǎo)電率。針對時效制度和成分對導(dǎo)電鋁合金性能的影響,。本課題的研究內(nèi)容主要分為兩個部分:第一部分主要研究雙級時效對合金綜合性能的影響,第二部分主要分析比較不同Cu含量的合金在相同時效制度下綜合性能的區(qū)別。時效制度的研究結(jié)果表明:與單級時效相比,雙級時效能夠提高6063合金峰值時效的硬度和過時效的硬度,合金的峰值平臺時間延長。在一級時效溫度90℃+二級時效溫度180℃的時效制度下,其抗拉強度、延伸率和電導(dǎo)率分別達到225MPa、12%和56.83%IACS能夠滿足使用要求。一級時效溫度主要影響合金時效初期的析出進程,能夠促進GP區(qū)的形成,并影響GP區(qū)的數(shù)分布。二級時效溫度控制合金隨后的析出進程,能夠決定合金在時效不同時間時析出相的類型如針狀β"相、桿狀β'相,這些析出相將最終決定合金的綜合性能。銅元素含量的研究結(jié)果表明,與導(dǎo)電軌用6063合金相比,Cu元素的加入能夠提高合金峰時效峰值硬度,但會降低合金的電導(dǎo)率。Al-0.8Mg-0.58Si-0.6Cu(wt.%)合金的綜合性能良好,其二級時效840min時的抗拉強度、延伸率和電導(dǎo)率分別為225MPa、11.5%和56.90%IACS,在滿足使用要求的同時進一步拓寬了工藝區(qū)間。Cu元素的加入能夠促進針狀β"相的析出,改變合金過時效階段不同析出相的比例。Al-Mg-Si(Cu)過時效階段強度提高主要歸因于過時效階段殘留的針狀β"相和板條狀Q'相。
[Abstract]:Al-Mg-Si-Cu) alloys have good mechanical properties such as low density, high strength, good ductility and high electrical conductivity. For example, the conductive rail used in rail transit has been widely used. Al-Mg-Si-Cu) alloy is a heat-treatable alloy. The strength of the alloy mainly depends on the precipitation of coherent or semi-coherent nanocrystalline precipitates at supersaturated A1 matrix. The electrical conductivity of the alloy is controlled by the number of solid solution elements. In a typical 6 series of aluminum alloys, the strength rises first and then decreases, while the conductivity increases continuously. This creates a contradiction between strength and electrical conductivity. The current supply state of the conductive rail is in an overaged state to meet the requirements of conductivity. The alloy composition and aging system determine the number of precipitates in the Al-Mg-Si-Cu) alloy, which not only affect the strength, but also the strength of the alloy. The main contents of this paper are divided into two parts: the first part mainly studies the effect of two-stage aging on the comprehensive properties of the alloy. The second part mainly analyzes and compares the comprehensive properties of alloys with different Cu content under the same aging regime. The double stage aging can increase the hardness of 6063 alloy and the hardness of overaging, and the peak plateau time of the alloy is prolonged. The tensile strength of 6063 alloy is increased at the aging temperature of 90 鈩，

本文編號：1534564