本文選題：5A06鋁合金 + 攪拌摩擦焊��； 參考：《太原科技大學(xué)》2017年碩士論文

【摘要】：攪拌摩擦焊技術(shù)是新型固相連接方法,可以有效解決傳統(tǒng)熔化焊接方法中易出現(xiàn)的熱裂紋、接頭熱影響區(qū)軟化及焊接變形等問題,為鋁合金等低熔點(diǎn)金屬的焊接提供了新方法。攪拌摩擦焊接過程復(fù)雜,而焊接溫度場(chǎng)能夠直觀地反映接頭溫度分布情況,通過溫度場(chǎng)的模擬研究可以進(jìn)一步了解其焊接機(jī)制,對(duì)焊接參數(shù)的優(yōu)化及避免缺陷形成具有重要指導(dǎo)意義。本文首先建立了5A06鋁合金攪拌摩擦焊接過程的熱輸入模型,采用ANSYS有限元分析軟件對(duì)不同工藝參數(shù)下的焊接溫度場(chǎng)進(jìn)行數(shù)值模擬,研究攪拌摩擦焊接過程溫度場(chǎng)分布規(guī)律以及攪拌頭轉(zhuǎn)速和焊接速度對(duì)溫度場(chǎng)的影響;通過對(duì)比模擬與試驗(yàn)方法所測(cè)熱循環(huán)結(jié)果,驗(yàn)證模型準(zhǔn)確性;使用超景深顯微鏡觀察焊縫表面成形、內(nèi)部缺陷及焊核區(qū)微觀組織;利用顯微硬度計(jì)測(cè)試接頭橫截面硬度。得到如下結(jié)論:溫度場(chǎng)模擬結(jié)果顯示焊縫中心溫度低于軸肩邊緣,軸肩外側(cè)峰值溫度隨距焊縫中心距離增大而降低,焊縫兩側(cè)溫度場(chǎng)對(duì)稱分布。攪拌頭轉(zhuǎn)速影響峰值溫度,而焊接速度影響峰值溫度停留時(shí)間,轉(zhuǎn)速增大,峰值溫度升高,焊速增大,峰值溫度停留時(shí)間減少。試驗(yàn)與模擬結(jié)果對(duì)比表明本文采用的熱量自適應(yīng)熱源模型能夠準(zhǔn)確模擬焊接過程溫度場(chǎng)分布規(guī)律。對(duì)于12 mm厚鋁合金,最佳焊接參數(shù)為ω=220 r/min,v=8 cm/min,此時(shí)焊縫峰值溫度達(dá)到377°C,材料軟化程度及流動(dòng)性較好,可以得到無缺陷、成形良好的焊縫。5A06鋁合金接頭顯微硬度與晶粒大小有關(guān),焊核區(qū)組織發(fā)生動(dòng)態(tài)再結(jié)晶,轉(zhuǎn)變?yōu)榫鶆蚣?xì)小等軸晶,該區(qū)域硬度值與母材相比提高了約15%,達(dá)到84 HV。在接頭橫截面硬度呈“n”型分布,而焊縫厚度方向上晶粒尺寸與硬度無明顯變化。攪拌頭轉(zhuǎn)速提高,焊核區(qū)晶粒長(zhǎng)大,顯微硬度有降低趨勢(shì);焊接速度對(duì)晶粒尺寸及顯微硬度影響較小。
[Abstract]:Friction stir welding (FSW) is a new solid-phase bonding method, which can effectively solve the problems such as hot crack, heat affected zone softening and welding deformation, which can be used to weld low melting point metals such as aluminum alloy. The process of friction stir welding is complex, and the welding temperature field can directly reflect the temperature distribution of the joint. Through the simulation of the temperature field, the welding mechanism can be further understood. It is of great significance to optimize the welding parameters and avoid the formation of defects. In this paper, the heat input model of 5A06 aluminum alloy friction stir welding process is established, and the numerical simulation of welding temperature field under different process parameters is carried out by using ANSYS finite element analysis software. The distribution of temperature field in friction stir welding process and the effect of rotating speed and welding speed of stir head on temperature field were studied, and the accuracy of the model was verified by comparing the results of heat cycle measured by simulation and test methods. The weld surface forming, internal defects and microstructure of the nuke zone were observed by using the hyperfield depth microscope, and the cross section hardness of the joint was measured by microhardness meter. The results show that the center temperature of the weld is lower than the edge of the shaft shoulder and the peak temperature of the outside side of the shaft shoulder decreases with the increase of the distance from the center of the weld and the temperature field on both sides of the weld is symmetrically distributed. The rotating speed of the mixing head affects the peak temperature, while the welding speed affects the residence time of the peak temperature, the rotational speed increases, the peak temperature increases, the welding speed increases, and the peak temperature residence time decreases. The comparison of experimental and simulation results shows that the heat adaptive heat source model can accurately simulate the distribution of temperature field in welding process. For 12mm thick aluminum alloy, the optimum welding parameter is 蠅 220rmin / min / 8 cm / min, and the peak weld temperature reaches 377 擄C, the softening degree and fluidity of the material are good, and there is no defect. The microhardness of the well-formed weld. 5A06 aluminum alloy joint is related to the grain size. Dynamic recrystallization takes place in the microstructure of the nugget zone, which is transformed into uniform fine equiaxed crystal. Compared with the base metal, the hardness of the region is increased by about 15%, reaching 84 HV. The hardness of the cross section of the joint is "n" distributed, but the grain size and hardness have no obvious change in the direction of weld thickness. With the increase of the rotating speed of the mixing head, the grain size in the nugget region grows and the microhardness decreases, and the effect of welding speed on the grain size and microhardness is small.
【學(xué)位授予單位】：太原科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TG453.9

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王麗;謝非;張書;;攪拌摩擦焊對(duì)5A02鋁合金微觀組織及硬度的影響[J];輕合金加工技術(shù);2016年03期

2 ;汽車工業(yè)攪拌摩擦焊技術(shù)應(yīng)用[J];現(xiàn)代焊接;2016年01期

3 張欣盟;楊景宏;王春生;韓鳳武;;攪拌摩擦焊技術(shù)及其應(yīng)用發(fā)展[J];焊接;2015年01期

4 蔣若蓉;李文亞;羅賢道;楊茜;;熱輸入對(duì)7075鋁合金攪拌摩擦焊接頭質(zhì)量的影響[J];電焊機(jī);2014年04期

5 李敬勇;周小平;董春林;董繼紅;;6082鋁合金雙軸肩攪拌摩擦焊試板溫度場(chǎng)研究[J];航空材料學(xué)報(bào);2013年05期

6 任志遠(yuǎn);張燕;金丹萍;呂波;;5052鋁合金薄板攪拌摩擦焊接頭組織和力學(xué)性能研究[J];熱加工工藝;2013年05期

7 曾友亮;陳宏佑;孫匯彬;周博芳;;攪拌摩擦焊數(shù)值模擬的研究現(xiàn)狀[J];現(xiàn)代焊接;2013年02期

8 方連軍;劉曉娟;高獻(xiàn)娟;;焊接技術(shù)在航空航天工業(yè)中的應(yīng)用[J];中國(guó)新技術(shù)新產(chǎn)品;2013年01期

9 宋驍;邢麗;黃春平;王善林;;攪拌摩擦焊工藝參數(shù)對(duì)2198鋁鋰合金焊縫成形及接頭力學(xué)性能的影響[J];機(jī)械工程材料;2012年07期

10 欒國(guó)紅;孟立春;;攪拌摩擦焊技術(shù)在列車制造中的發(fā)展和應(yīng)用[J];金屬加工(熱加工);2010年16期

相關(guān)博士學(xué)位論文 前1條

1 謝廣明;攪拌摩擦焊接鎂及銅合金的微觀組織和力學(xué)性能[D];哈爾濱工業(yè)大學(xué);2008年

相關(guān)碩士學(xué)位論文 前6條

1 王冰;6082-T6鋁合金攪拌摩擦焊接頭微觀組織及力學(xué)性能的研究[D];吉林大學(xué);2015年

2 甘文英;5A30鋁合金攪拌摩擦焊接過程中微觀組織及性能研究[D];重慶大學(xué);2014年

3 徐偉;攪拌摩擦焊接過程三維熱流耦合模型研究[D];南昌航空大學(xué);2013年

4 陳婷;攪拌摩擦焊溫度場(chǎng)數(shù)值模擬研究[D];東北大學(xué);2012年

5 李仲華;攪拌摩擦焊接5083鋁合金焊縫組織與性能研究[D];廣東工業(yè)大學(xué);2011年

6 蘇曉莉;5A02鋁合金攪拌摩擦焊接工藝及溫度場(chǎng)研究[D];西安建筑科技大學(xué);2006年

，

本文編號(hào)：1917619