本文選題：鋁合金 + 冷金屬過(guò)渡焊(CMT)��； 參考：《沈陽(yáng)工業(yè)大學(xué)》2017年碩士論文

【摘要】：由于鋁及鋁合金具有優(yōu)異的性能,在多領(lǐng)域應(yīng)用廣泛,所以鋁合金結(jié)構(gòu)的高質(zhì)量焊接具有重要的意義。鋁合金常用的傳統(tǒng)焊接方法有TIG焊及MIG焊等,這些焊接技術(shù)比較成熟。但是它們也存在各自的不足,如TIG焊生產(chǎn)效率較低、鎢極承載電流能力差易造成焊縫金屬夾鎢,MIG焊存在裂紋、氣孔、未熔合、未焊透及焊接變形等焊接缺陷。冷金屬過(guò)渡焊(CMT焊)技術(shù)具有焊接熱輸入低,無(wú)飛濺等優(yōu)點(diǎn),適合鋁合金焊接。但是CMT焊接技術(shù)是近幾年面向市場(chǎng),所以焊接工藝及焊接性能有待進(jìn)一步研究。本文分別以2mm板厚的1060鋁合金和6082-T6鋁合金為試驗(yàn)材料,填充材料分別為直徑1.2mm的ER1100純鋁焊絲和ER4043鋁硅焊絲。通過(guò)優(yōu)化工藝參數(shù),確定了最佳工藝參數(shù)。利用金相顯微鏡(OM)、掃描電子顯微鏡(SEM)、能譜分析儀(EDS)和X射線衍射儀(XRD)對(duì)焊縫成形、顯微組織、相組成進(jìn)行了研究。利用顯微維氏硬度計(jì)測(cè)量了焊接接頭硬度分布;利用萬(wàn)能拉伸試驗(yàn)機(jī)測(cè)量焊接接頭拉伸力學(xué)性能。試驗(yàn)結(jié)果表明,1060鋁合金CMT焊接最佳工藝參數(shù)為焊接電流90A、焊接速度110cm/min、弧長(zhǎng)修正系數(shù)0%。在最佳工藝參數(shù)下,焊縫成形美觀。1060鋁合金CMT焊縫金屬組織主要由α-Al固溶體組成,結(jié)晶形態(tài)從熔合線到焊縫中心主要以柱狀晶形態(tài)生長(zhǎng)。焊縫金屬硬度約為28-30HV,熱影響區(qū)硬度約為27-32HV,母材金屬硬度約為36-39HV。焊接接頭抗拉強(qiáng)度約為64.45MPa,約是母材抗拉強(qiáng)度(87MPa)的70%,延伸率約為4.77%,斷裂位置在熱影響區(qū),斷口形貌表現(xiàn)為塑性斷口。6082-T6鋁合金CMT焊接最佳工藝參數(shù)為焊接電流105A、焊接速度110cm/min、弧長(zhǎng)修正系數(shù)0%。在最佳工藝參數(shù)下,焊縫正面成形均勻,背面焊透,焊縫成形良好。6082-T6鋁合金CMT焊縫金屬組織主要由α-Al固溶體和少量Mg2Si金屬間化合物組成,α-Al固溶體的結(jié)晶形態(tài)由熔合線到焊縫中心依次由胞狀晶、柱狀晶及等軸晶組成。焊縫金屬硬度約為65-73HV,熱影響區(qū)硬度約為60-95HV,母材金屬硬度約為95-98HV。焊接接頭抗拉強(qiáng)度約為188.52MPa,約是母材抗拉強(qiáng)度(310.24MPa)的61%,延伸率約為3.09%,斷裂位置在熱影響區(qū),拉伸斷口形貌表現(xiàn)為塑形斷口。
[Abstract]:Because aluminum and aluminum alloys have excellent properties and are widely used in many fields, high quality welding of aluminum alloy structures is of great significance. TIG welding and MIG welding are common traditional welding methods for aluminum alloy. However, they also have their own shortcomings, such as low production efficiency of TIG welding and poor bearing current capacity of tungsten electrode, which can easily lead to welding defects such as cracks, porosity, non-fusion, failure to weld penetration and welding deformation in weld metal intercalated tungsten MIG welding. Cold metal transfer welding (CMT) technology has the advantages of low heat input and no spatter, so it is suitable for aluminum alloy welding. However, CMT welding technology is market-oriented in recent years, so welding process and welding performance need further study. In this paper, 1060 aluminum alloy and 6082-T6 aluminum alloy with thickness of 2mm plate were used as experimental materials, and the filling materials were ER1100 pure aluminum wire with diameter 1.2mm and ER4043 Al-Si wire with diameter respectively. The optimum process parameters are determined by optimizing the process parameters. Metallographic microscope (OM), scanning electron microscope (SEM), energy dispersive analyzer (EDS) and X-ray diffraction (XRD) were used to study the formation, microstructure and phase composition of the weld. Hardness distribution of welded joints was measured by microhardness tester and tensile mechanical properties of welded joints were measured by universal tensile testing machine. The experimental results show that the optimum welding parameters for CMT of 1060 aluminum alloy are welding current 90A, welding speed 110 cm / min, arc length correction coefficient 0. Under the optimum process parameters, the microstructure of CMT weld metal formed by beautiful. 1060 aluminum alloy is mainly composed of 偽 -Al solid solution, and the crystal morphology mainly grows in columnar form from the fusion line to the center of the weld. The hardness of weld metal is about 28-30HV. the hardness of heat-affected zone is about 27-32HV. the hardness of base metal is about 36-39HV. The tensile strength of the welded joint is about 64.45 MPA, which is about 70 of the base material tensile strength (87MPa), and the elongation is about 4.777.The fracture position is in the heat-affected zone. The fracture morphology is: plastic fracture. 6082-T6 aluminum alloy CMT welding parameters: welding current 105A, welding speed 110 cm / min, arc length correction coefficient 0. Under the optimum process parameters, the weld face is formed evenly, and the back side is fully welded. The microstructure of CMT weld metal is mainly composed of 偽 -Al solid solution and a small amount of mg _ 2Si intermetallic compound. The crystal morphology of 偽 -Al solid solution is composed of cellular crystal, columnar crystal and equiaxed crystal from fusion line to weld center. The hardness of weld metal is about 65-73HV. the hardness of heat-affected zone is about 60-95HV. the hardness of base metal is about 95-98HV. The tensile strength of the welded joint is about 188.52 MPa, which is about 61% of the base material tensile strength (310.24 MPA), and the elongation is about 3.09. The fracture position is in the heat-affected zone, and the tensile fracture appearance is shaped fracture.
【學(xué)位授予單位】：沈陽(yáng)工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TG457.14

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 湯沛;王淼;;6082-T6鋁合金攪拌摩擦焊接頭組織和力學(xué)性能研究[J];熱加工工藝;2017年01期

2 王鋒;遲長(zhǎng)志;臺(tái)立民;馬盛堯;孫凱;;鋁硅合金變質(zhì)處理研究現(xiàn)狀[J];熱加工工藝;2016年11期

3 陳樹(shù)君;趙昀;肖s，

本文編號(hào)：2064924