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采用电子束焊接工艺对21 mm厚TC18钛合金板进行了1次与2次(在1次焊接焊缝处以相同工艺再次焊接)焊接试验,研究了焊接次数对接头组织、拉伸性能和硬度的影响。结果表明:2种焊接接头均成形良好,无明显缺陷;相对于1次焊接,2次焊接接头热影响区中的α′相增多,晶粒尺寸增大;焊接接头的抗拉强度高于母材,且2次焊接接头强度更高,但断后伸长率下降,断裂方式均为韧性断裂;1次焊接与2次焊接接头焊缝区的平均显微硬度分别为380,395 HV,均高于母材区,热影响区的平均显微硬度分别为360,350 HV,增加焊接次数提高了焊缝区硬度,降低了热影响区硬度。 相似文献
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通过显微硬度计、拉伸试验机、扫描电镜和X射线衍射仪等研究了激光填丝焊接6mm厚6061铝合金接头的显微组织和力学性能。结果表明:焊缝中心区域的显微组织为等轴晶,由α-Al固溶体组成,无β(Mg_2Si)强化相析出,近熔合区的焊缝组织为柱状晶;焊接接头焊缝的硬度最低,约为73HV,母材的硬度最高,约为110HV,随着距焊缝中心距离的增大,热影响区的硬度先呈波浪式增大,在距焊缝中心2.2~3.8 mm处有所下降,此外为热影响区软化区,在距焊缝中心3.8~4.4mm处又快速增大;焊接接头的抗拉强度为234 MPa,约为母材的71%,高于熔化极惰性气体保护焊接接头的;焊接接头均在焊缝处断裂,接头与母材均为韧性断裂。 相似文献
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采用激光-TIG复合热源填丝焊接5 mm厚T651态6061铝合金,研究电弧电流对复合填丝焊接焊缝成形的影响,分析了优化工艺参数下的焊缝显微组织及显微硬度特征,并与单独TIG填丝焊接进行综合对比。结果表明:采用激光-TIG复合热源填丝焊接T651态6061铝合金,能够有效改善焊缝成形,当TIG电弧电流为140 A时焊接过程稳定,焊缝成形效果良好;复合填丝焊接焊缝中心区域的显微组织为等轴晶,熔合区组织由大量枝状晶组成;复合填丝焊接显微硬度高于单独TIG填丝焊接,焊缝区均存在软化现象,在选择的测试点范围内,复合填丝焊接焊缝中心区域的平均硬度为66.91 HV,约为母材硬度的62.0%,比单独TIG填丝焊接提高约13.1%。 相似文献
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《机械工程材料》2016,(12)
对D406钢和20钢进行了角焊接,研究了异质钢焊接接头的显微组织和力学性能,此外还研究了D406钢对接接头的力学性能。结果表明:此异质钢焊接接头D406钢侧焊缝区的显微组织主要以板条马氏体为主,熔合区主要是针状马氏体,该区是接头中最易产生裂纹的区域;D406A钢侧焊接接头热影响区靠近焊缝处的硬度最大,约为659 HV;20钢侧焊接接头焊缝区的最高硬度约为350HV,低于D406A钢侧的最高硬度,因而D406A钢侧热影响区的淬硬倾向相对较大;D406A钢对接接头熔合区的冲击功小于母材和焊缝区的冲击功,该焊接接头的拉伸试样均断裂于在焊缝区,抗拉强度的平均值为679 MPa,这与其焊缝区的组织为板条马氏体有很大关系。 相似文献
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2Cr13马氏体不锈钢的激光焊接组织及性能研究 总被引:1,自引:0,他引:1
利用OM、显微硬度仪和电子万能试验机对激光焊接2Cr13马氏体不锈钢的接头显微组织、硬度和抗拉强度进行了研究。结果表明:焊缝中心区组织为等轴晶、近中心区为柱状晶,熔合区为枝状晶和少量的胞状晶,热影响区(H.A.Z)主要由针状马氏体组织组成;焊缝中心区最高硬度约为Hv330,H.A.Z的平均硬度约为Hv265,基材平均硬度约为Hv270,从H.A.Z到基材硬度明显下降;焊接接头的抗拉强度平均值为491 MPa,宏观断口为脆性断裂特征。 相似文献
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钛合金广泛应用于工业生产,TC系列钛合金是其中应用最广的一种。以TC系列钛合金作为典型,对其进行激光焊接性能分析,并针对焊接性能开展激光焊接工艺分析,对TC系列及其他类型钛合金激光焊接加工具有一定现实指导意义。 相似文献
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Effects on mechanical properties in electron beam welding of TC4 alloy by laser shock processing 总被引:1,自引:0,他引:1
Lu Jinzhong Zhang Yongkang Kong Dejun Ren Xudong Ge Tao Zou Shikun 《Frontiers of Mechanical Engineering in China》2007,2(4):478-482
The surface of TC4 titanium alloy welding line by electron beam welding (EBW) was processed by high power Q-switched and repetition-rate
Nd: glass laser. Effects of laser power and spot diameter on residual stress and microhardness of the TC4 alloy welding line
by laser shock processing (LSP) have been analyzed. Results show that residual stresses almost do not change as laser power
is 45.9 J, spot diameter is ϕ9 mm; While laser power is 45.9 J, spot diameter less than ϕ3 mm, the distribution of residual
stress in welding line occurs obvious variation, which residual stress increase obviously with spot diameter decrease. When
power density is bigger than 1.8 × 1010 W/cm2, residual stresses of electron beam welding line occur change by LSP, which improve obviously residual stress distribution;
while laser power is bigger than 1.2 × 1010 W/cm2, the surface micro-hardness of electron beam welding line occurs change by LSP, which improve obviously micro-hardness distribution.
Mechanical properties of TC4 titanium alloy welding line will be improved by LSP, which provides experimental foundation for
further controlling the distributions of residual stress and micro-hardness during laser shock processing.
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Translated from Journal of Jiangsu University (Natural Science), 2006, 27(3): 207–210 [译自: 江苏大学学报 (自然科学版)] 相似文献
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TC4钛合金精密焊接工艺研究 总被引:4,自引:0,他引:4
针对TC4钛合金,采用电子束焊接和激光束焊接两种方法,对焊深及其波动,焊接质量,焊接变形等方面进行了分析,获得了外观成型良好,色泽正常的焊接接头,经过X射线探伤,焊缝内部质量达到国际GB3233-87Ⅱ级要求,实现了TC4钛合金的精密焊接。 相似文献
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低功率激光诱导电弧复合焊接钛合金薄板工艺研究 总被引:4,自引:0,他引:4
采用低功率脉冲YAG激光诱导非熔化极惰性气体保护(Tungsten inert gas,TIG)焊电弧复合热源实现了1 mm厚TC4钛合金薄板的优质焊接,研究激光诱导电弧复合焊接过程中热源能量匹配、热源间角度、对接间隙对焊缝成形的影响规律。结果表明,钛合金薄板低功率脉冲YAG激光诱导TIG电弧复合热源焊接过程中,激光能量与电弧能量之间的相互匹配将显著影响焊缝的表面成形。相对于电弧功率的变化,焊缝成形对激光功率变化的敏感度更高。随着热源间角度减小,激光诱导电弧复合热源传热能力增强;由于复合焊接速度快、热输入小、焊接试板横向变形小,当对接间隙为0~0.5 mm范围内时均能获得良好的焊缝成形。为了使焊缝成形均匀连续,焊接过程中需要对焊缝背面采用氩气进行保护,当保护气体流量为5~8L/min时获得最佳焊接接头。 相似文献
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对TC4钛合金单面修饰激光焊接接头进行激光冲击强化,对比强化前后焊接接头的疲劳寿命,在光学显微镜和扫描电镜下观察断口疲劳断裂特征,并从焊接接头的显微硬度、微观组织、残余应力分布等方面综合分析激光冲击强化对TC4钛合金单面修饰激光焊接接头的强化机理。试验结果表明:未强化和强化试样均在焊缝咬边处萌生疲劳裂纹,强化试样疲劳寿命是未强化试样疲劳寿命的3.77~9.15倍,强化试样焊缝咬边处马氏体细化,显微硬度提高,焊缝表面呈残余压应力分布,焊缝咬边处残余压应力达-564.37±9.85MPa。晶粒细化和高幅值残余压应力综合作用下抑制了焊缝咬边处疲劳裂纹的萌生,且增大了裂纹扩展阻力,从而提高了焊接接头疲劳性能。 相似文献
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Investigation on weldability of magnesium alloy thin sheet T-joints: arc welding, laser welding, and laser-arc hybrid welding 总被引:2,自引:1,他引:1
Chenbin Li Liming Liu 《The International Journal of Advanced Manufacturing Technology》2013,65(1-4):27-34
Four welding methods, including laser welding, gas tungsten arc (GTA) welding, laser–GTA hybrid welding, and laser–GTA hybrid welding with cold welding wire, are used to investigate the weldability of T-joints of magnesium alloy thin sheet. Stake welding process is presented in this paper in order to overcome the defects, such as stress concentration and deformation, and improve the accessibility of T-joints in fillet welding process. The effect of heat source type on weldability of T-joints is analyzed. The microstructures and mechanical properties are investigated. Experimental results indicate that comparing with the other three welding methods, laser–GTA hybrid welding with cold welding wire is the most effective process for T-joints of magnesium alloy thin sheet. In this process, T-joints are full penetration and the toes are smooth and round, and besides, reinforcement forms on the upside of weld bead by the filled wire. The mechanical properties of T-joints made with laser–GTA hybrid welding with cold welding wire achieve 90 % of that of base metal and are superior to that without welding wire. 相似文献
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Hui-Chi Chen Andrew J. Pinkerton Lin Li 《The International Journal of Advanced Manufacturing Technology》2011,52(9-12):977-987
Challenges in dissimilar materials welding are the differences of physical and chemical properties between welding materials and the formation of intermetallic brittle phases resulting in the degradation of mechanical properties of welds. However, dissimilar materials welding is increasingly demanded from the industry as it can effectively reduce material costs and improve the design. In aerospace applications, Ti-6Al-4V titanium alloy and Inconel 718 nickel alloy have been widely used because of their superior corrosion resistance and mechanical properties. In this study, a single-mode continuous-wave fibre laser was used in butt welding of Ti-6Al-4V to Inconel 718. Investigations including metallurgical and mechanical examinations were carried out by means of varying processing parameters, such as laser power, welding speed and the laser beam offset position from the interface of the metals. Simple analytical modelling analysis was undertaken to explain the phenomena that occurred in this process. Results showed that the formation of intermetallic brittle phases and welding defects could be effectively restricted at welding conditions produced by the combination of higher laser power, higher welding speed and shifting the laser beam from the interface to the Inconel 718 alloy side. The amount of heat input and position of laser beam to improve the Ti-6Al-4V/Inconel 718 weld quality are suggested. 相似文献
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对TC11/LF6钛铝异种金属进行了连续驱动摩擦焊接工艺及其焊后热处理工艺的研究,观察了热处理前后焊接接头焊合区微观组织并测定了试样力学性能。研究结果表明:未经热处理的焊接接头晶粒较为粗大,有明显的晶间化合物产生,接头显微硬度较高;经280℃退火1h后,焊接接头晶粒均匀细化,焊接界面产生较薄的不连续扩散层;热处理后接头晶粒明显细化,抗弯强度提高10.7%,显微硬度下降38%。通过组织和力学性能综合分析,得到最优化的TC11/LF6连续驱动摩擦焊接工艺参数。 相似文献