本文選題：6082鍛造鋁合金　切入點：熱變形　出處：《長春工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著科學(xué)技術(shù)的發(fā)展,高質(zhì)量、低成本、無污染將是汽車市場競爭能力和企業(yè)經(jīng)濟(jì)效益提高的核心所在。而合理使用材料,尤其是汽車重要零件的材料和充分發(fā)揮材料潛力的熱處理技術(shù),將起著重要作用。汽車控制臂是將車輪受到的力傳遞到車身,使車輪在特定軌跡行駛的關(guān)鍵構(gòu)件,其質(zhì)量與使用者的人身安全密切相關(guān),對剛度、強(qiáng)度、使用壽命的要求非常高。棒材直接機(jī)械加工件和鑄造成型件的力學(xué)性能較差,不能達(dá)到控制臂的使用性能要求,因此鍛造技術(shù)是主要加工方法。在鋁合金鍛造生產(chǎn)過程中,由于控制臂的形狀復(fù)雜,成型比較困難,同時受鋁合金成型特點的影響,其中性能不均勻(強(qiáng)度合格塑性不足、塑性合格強(qiáng)度不足)的現(xiàn)象比較常見,這也是目前國內(nèi)外生產(chǎn)商所面臨的共同問題。本論文以6082鍛造鋁合金控制臂為研究對象。首先,研究了6082鋁合金的高溫塑性變形行為,分析此種合金的流變應(yīng)力行為隨變形溫度、應(yīng)變速率的變化規(guī)律及內(nèi)部組織結(jié)構(gòu)的演變過程,評價熱變形過程中變形條件對性能的影響因素,為優(yōu)化此種合金擠壓、軋制、鍛造熱加工工藝提供參考。其次,為繼續(xù)提高該鍛造合金控制臂的綜合使用性能提供依據(jù),探討了固溶、時效處理對此合金微觀組織結(jié)構(gòu)及力學(xué)性能的影響規(guī)律。在壓縮實驗機(jī)(帶有自制控溫箱)上進(jìn)行高溫變形實驗,得到6082鍛造鋁合金的真應(yīng)力-真應(yīng)變曲線,建立了此合金高溫應(yīng)力-應(yīng)變本構(gòu)方程及流變應(yīng)力本構(gòu)方程。利用金相顯微鏡觀察了該合金高溫壓縮時,在一定變形溫度、變形速率內(nèi)微觀組織結(jié)構(gòu)的變化規(guī)律。結(jié)果表明,高溫變形實驗中,動態(tài)回復(fù)是所述鍛造鋁合金的主要軟化機(jī)制;變形溫度下降或應(yīng)變速率增加,晶粒度隨之增大。利用場發(fā)射掃描電子顯微鏡觀察材料組織結(jié)構(gòu),并檢測析出第二相的成分,探討不同固溶、時效處理參數(shù)對材料微觀組織與析出相的影響規(guī)律;利用XRD衍射分析儀對固溶及時效后析出相的種類進(jìn)行檢測;利用壓縮實驗機(jī)檢測各個實驗樣品的力學(xué)性能。結(jié)果表明,組織中主要包括球狀、針狀的Mg2Si與棒狀的AlFe(Mn)Si兩種第二相;在熱處理過程中,AlFe(Mn)Si相的尺寸、數(shù)量及分布不隨熱處理的溫度及時間發(fā)生變化,對力學(xué)性能起主要作用的是Mg2Si相;固溶溫度為555℃、固溶時間為2 h,空氣中滯留5 s進(jìn)行水淬,時效溫度為170℃、時效時間為8 h是6082鍛造鋁合金控制臂的最佳工藝參數(shù)。
[Abstract]:With the development of science and technology, high quality, low cost and no pollution will be the core of improving the competitive power of automobile market and the economic benefit of enterprises. Especially the material of the important parts of the automobile and the heat treatment technology which can give full play to the potential of the material will play an important role. The control arm of the automobile is the key component to transfer the force of the wheel to the body and make the wheel travel on a specific track. The quality is closely related to the personal safety of the user, and the requirements for stiffness, strength and service life are very high. Therefore, forging technology is the main processing method. In the process of aluminum alloy forging, due to the complex shape of the control arm and the difficulty of forming, and influenced by the forming characteristics of aluminum alloy, the properties of the aluminum alloy are not uniform and the strength qualified plasticity is not enough. The phenomenon of insufficient plastic qualified strength) is a common problem faced by domestic and foreign manufacturers at present. In this paper, 6082 aluminum alloy control arm is taken as the research object. Firstly, the plastic deformation behavior of 6082 aluminum alloy at high temperature is studied. The rheological stress behavior of the alloy with deformation temperature, strain rate and evolution process of internal microstructure is analyzed, and the influence factors of deformation conditions on properties during hot deformation are evaluated, in order to optimize the extrusion and rolling of the alloy, Secondly, it provides the basis for improving the comprehensive performance of the control arm of the forging alloy, and discusses the solid solution. The effect of aging treatment on the microstructure and mechanical properties of the alloy was studied. The true stress-strain curves of 6082 forged aluminum alloy were obtained by high temperature deformation experiments on a compression test machine (with a self-made temperature control box). The high temperature stress-strain constitutive equation and rheological stress constitutive equation of the alloy were established. The microstructure of the alloy under high temperature compression was observed under certain deformation temperature and deformation rate. In high temperature deformation experiment, dynamic recovery is the main softening mechanism of the wrought aluminum alloy. The grain size increases with the decrease of deformation temperature or the increase of strain rate. The microstructure of the alloy is observed by field emission scanning electron microscope. The composition of the second phase was detected, and the influence of different solid solution and aging treatment parameters on the microstructure and precipitation phase of the material was discussed, and the kinds of precipitated phase after solution and aging were detected by XRD diffraction analyzer. The mechanical properties of each sample were tested by compression test machine. The results showed that the microstructure consisted mainly of spherical, needle-like Mg2Si and rod-like AlFe(Mn)Si, and the size of AlFeFeMnMn-Si phase during heat treatment. The quantity and distribution do not change with the temperature and time of heat treatment, the main effect on mechanical properties is the Mg2Si phase, the solution temperature is 555 鈩，

本文編號：1637246