本文選題：鋁合金多層結(jié)構(gòu)　切入點(diǎn)：釬焊　出處：《南京理工大學(xué)》2017年碩士論文

【摘要】：目前,國(guó)內(nèi)外雷達(dá)天線和散熱器廣泛采用鋁合金薄壁復(fù)雜多層結(jié)構(gòu)。鋁合金多層結(jié)構(gòu)具有形狀復(fù)雜、通道壁薄、焊接面狹窄、尺寸形位精度要求高及制造難度大的特點(diǎn),所以鋁合金多層結(jié)構(gòu)普遍存在焊接質(zhì)量不穩(wěn)定、成品率不高的問題。本文本文采用了釬焊、釬接-擴(kuò)散復(fù)合焊接和擴(kuò)散焊方法連接鋁合金多層結(jié)構(gòu),通過研究焊接接頭的界面組織結(jié)構(gòu),分析了不同工藝參數(shù)對(duì)接頭界面、力學(xué)性能及變形量的影響,并通過ANSYS有限元分析軟件,從而有效地指導(dǎo)了控制零件焊接變形的試驗(yàn),最終獲得了比較理想的焊接接頭。采用Al-Si-Mg釬料對(duì)3A21鋁合金多層結(jié)構(gòu)進(jìn)行了釬焊試驗(yàn),在釬焊溫度610℃,保溫時(shí)間10min條件下獲得最佳接頭,強(qiáng)度可達(dá)72 MPa。采用Al-Si-Mg釬料對(duì)3A21鋁合金多層結(jié)構(gòu)進(jìn)行了釬接-擴(kuò)散復(fù)合焊接試驗(yàn),在釬焊溫度610℃,保溫時(shí)間10 min,擴(kuò)散焊溫度560℃,壓力0.5 MPa,擴(kuò)散時(shí)間60 min下,獲得理想接頭,強(qiáng)度達(dá)到81 MPa。由于釬焊后的擴(kuò)散焊使得釬焊中容易出現(xiàn)的未焊合和空洞等缺陷得以消除,元素?cái)U(kuò)散更充分,因此釬接-擴(kuò)散復(fù)合焊接所得接頭質(zhì)量明顯好于釬焊接頭。對(duì)3A21鋁合金多層復(fù)雜結(jié)構(gòu)焊接接頭焊縫進(jìn)行了EDS分析,兩種方法的釬料與母材的元素均均勻擴(kuò)散,且釬接-擴(kuò)散復(fù)合焊接元素?cái)U(kuò)散更均勻。焊縫都主要包括蜂窩狀的Al基體、塊狀富Si相和初晶Si等。另外還出現(xiàn)Mg和Si形成Mg2Si強(qiáng)化相,提高了接頭性能。采用直接擴(kuò)散焊焊接了 6061鋁合金多層結(jié)構(gòu),在焊接溫度560℃,焊接壓力為4 MPa,保溫時(shí)間為60 min下所得的最佳接頭強(qiáng)度達(dá)到140 MPa;加Al-Si中間層擴(kuò)散焊,在焊接溫度為580℃,焊接時(shí)間為30min,焊接壓力2MPa,焊接溫度為520℃,焊接時(shí)間為60min,焊接壓力為1MPa下所得接頭具有更好的接頭質(zhì)量和更高的接頭強(qiáng)度,強(qiáng)度達(dá)到150 MPa。對(duì)6061鋁合金多層復(fù)雜結(jié)構(gòu)擴(kuò)散連接接頭焊縫進(jìn)行了元素與組織分析,焊縫都主要包括α-Al基體相、Al4Si相、單質(zhì)Si相和Mg2Si強(qiáng)化相等。采用分段加壓的方法顯著減小了變形量,變形率比只采用恒定壓力的變形率減小了 0.3%。在有限元模擬結(jié)果的指導(dǎo)下,有針對(duì)性的設(shè)計(jì)和優(yōu)化了焊接方法及工藝參數(shù),從而有效地控制了零件的焊接變形。
[Abstract]:At present, aluminum alloy thin wall complex multilayer structure is widely used in radar antenna and radiator at home and abroad. Aluminum alloy multilayer structure has the characteristics of complex shape, thin channel wall, narrow welding joint, high precision of dimension and position and high difficulty in manufacturing. Therefore, the welding quality is unstable and the product rate is not high in the multilayer structure of aluminum alloy. In this paper, brazing, brazing and diffusion welding are used to connect the multilayer structure of aluminum alloy. The influence of different process parameters on the interface, mechanical properties and deformation of welded joints is analyzed by studying the interface structure of welded joints, and the ANSYS finite element analysis software is used to guide the experiment of controlling welding deformation effectively. Finally, an ideal welding joint was obtained. The multilayer structure of 3A21 aluminum alloy was brazed with Al-Si-Mg filler metal. The best joint was obtained under the condition of brazing temperature 610 鈩，

本文編號(hào)：1685514