本文選題：分流模 + 焊合　； 參考：《天津理工大學(xué)》2015年碩士論文

【摘要】：平面分流模具的工作原理是采用實(shí)心鑄錠,在擠壓力作用下,使鑄錠在經(jīng)過(guò)分流孔時(shí)被分為幾股金屬流,然后在高溫、強(qiáng)擠壓力和真空的環(huán)境下,在焊合室內(nèi)被重新焊合在一起,最后通過(guò)符合型材斷面尺寸要求的定徑帶流出,從而形成了符合一定尺寸、形狀的空心型材。分流模擠壓的生產(chǎn)效率高,生產(chǎn)周期短,并能生產(chǎn)斷面復(fù)雜、壁厚差大的型材,在生產(chǎn)管材、空心型材中得到了廣泛的應(yīng)用。但是,平面分流模擠壓同樣存在一定的缺陷,即分流后的幾股金屬流在焊合室內(nèi)焊合后存在焊縫,鋁合金結(jié)構(gòu)型材的強(qiáng)度較差的位置一般就在焊縫處。所以,提高平面分流模擠壓工藝的焊合質(zhì)量對(duì)型材質(zhì)量有著至關(guān)重要的影響。分流模擠壓的焊合研究,首先通過(guò)研究一個(gè)多孔鋁合金扁管的擠壓工藝來(lái)引入。該鋁合金管主要應(yīng)用于汽車(chē)空調(diào)散熱器中,其特點(diǎn)在于超薄、輕量及其良好的散熱性與耐腐蝕性。研究改進(jìn)了擠壓該超薄鋁合金管的模具結(jié)構(gòu),效仿蝶形模具的結(jié)構(gòu)形式,將分流橋的前后端設(shè)計(jì)為“弓形”,并使用有限元模擬技術(shù)對(duì)管材擠壓過(guò)程進(jìn)行模擬。Deform-3D的模擬結(jié)果表明,“弓形”結(jié)構(gòu)減小了坯料分流時(shí)的突破擠壓力,加快了橋后金屬的流動(dòng)速度,增加了備料區(qū)的金屬量,有利于金屬焊合。文章還著重對(duì)分流比的選擇進(jìn)行了詳細(xì)地分析。對(duì)12組不同的分流比K值分別進(jìn)行了建模、有限元模擬分析,進(jìn)而進(jìn)行對(duì)比,找出了最佳的分流比K值。經(jīng)過(guò)研究,分流比值選擇16時(shí)擠壓模擬結(jié)果最佳。文章對(duì)三角孔超薄鋁合金管的擠壓也進(jìn)行了研究,通過(guò)增加分流比,減小摩擦,減慢擠壓速度,提高擠壓溫度等方法,最終在模擬結(jié)果中實(shí)現(xiàn)了金屬比較好的焊合。而針對(duì)平面分流模擠壓工藝的特點(diǎn),采用一個(gè)靜態(tài)擠壓實(shí)驗(yàn)來(lái)探索鋁合金在高溫、強(qiáng)壓力下實(shí)現(xiàn)高質(zhì)量焊合的條件。實(shí)驗(yàn)是在高溫、強(qiáng)擠壓力下,將兩個(gè)完全相同的3003鋁合金錠坯擠壓為一體,并討論焊縫變化的情況。實(shí)驗(yàn)的結(jié)果表明,擠壓焊合的焊縫質(zhì)量與溫度、擠壓速度、壓力等參數(shù)均有關(guān)聯(lián)。而具有側(cè)向流動(dòng)的金屬芯部層,其焊縫的質(zhì)量更高。最后,設(shè)計(jì)了一種分流模成型管材擠脹組合模具,包括分流擠壓模具部分和脹形模具部分。設(shè)計(jì)的初衷是利用該擠脹組合模具進(jìn)行脹形實(shí)驗(yàn),以檢驗(yàn)鋁合金管焊合帶質(zhì)量。
[Abstract]:The working principle of the plane split die is to adopt solid ingot, under the action of extrusion force, the ingot is divided into several metal flows when passing through the shunt hole, and then in the environment of high temperature, strong extrusion pressure and vacuum. After being welded together again in the welding chamber, the hollow profile with certain size and shape is formed through the flow of the sizing strip which meets the requirements of the section size of the profile. The extrusion of split die has high production efficiency, short production cycle, and can produce sections with complex section and large wall thickness difference. It has been widely used in the production of pipe and hollow profile. However, there are some defects in the extrusion of plane split die, that is, there are weld lines after welding in the welding chamber, and the position where the strength of the aluminum alloy structure profile is poor is generally located at the weld seam. Therefore, it is very important to improve the welding quality of the extrusion process. Firstly, the extrusion process of a porous aluminum alloy flat tube is studied. The aluminum alloy tube is mainly used in automobile air conditioning radiator, which is characterized by super thin, light weight and good heat dissipation and corrosion resistance. The die structure of extruding the ultra-thin aluminum alloy tube is studied and improved, and the front and rear end of the shunt bridge is designed as "bow", following the structure of butterfly die. The finite element simulation technique is used to simulate the tube extrusion process. Deform-3D simulation results show that the "bow" structure reduces the breakthrough extrusion pressure when the blank is divided, accelerates the metal flow rate behind the bridge, and increases the metal content in the material preparation area. It is favorable for metal welding. The selection of shunt ratio is analyzed in detail. The K value of 12 groups of different shunt ratio was modeled and simulated by finite element method, and the best value of K value was found out. Through the research, the best result of the 16:00 extrusion simulation was chosen as the shunt ratio. The extrusion of ultra-thin aluminum alloy tube with triangle hole is also studied in this paper. By increasing the flow ratio, reducing friction, slowing down extrusion speed and increasing extrusion temperature, the welding bonding of metal is realized in the simulation results. According to the characteristics of the extrusion process of the plane split die, a static extrusion experiment was used to explore the conditions of high quality welding of aluminum alloy under high temperature and high pressure. Two identical 3003 aluminum alloy ingot billets were extruded under high temperature and strong extrusion pressure, and the change of weld seam was discussed. The results show that the welding quality is related to temperature, extrusion speed and pressure. The weld quality of the core layer with lateral flow is higher. Finally, a split die forming tube extrusion die is designed, including the split extrusion die part and the bulging die part. The original intention of the design is to test the quality of welded strip of aluminum alloy pipe by means of bulging test.
【學(xué)位授予單位】：天津理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TG379

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本文編號(hào)：1974405