共查询到19条相似文献,搜索用时 203 毫秒
1.
《焊接》2016,(12)
从TIG电弧波动特征方面分别研究了铝合金高功率单光束激光-TIG复合焊和双光束激光-TIG复合焊焊接过程的差别。试验结果表明,双光束-TIG复合焊的电弧电压分布更集中,即双光束-TIG复合焊的电弧电压相对稳定。在试验条件下,当焊接参数相同时,双光束-TIG电弧电压的变异系数随激光功率的增加而减小,单光束-TIG的电弧电压变异系数随激光功率的增加而增加,并且在激光功率密度较小时,单光束-TIG的电压变异系数小于双光束-TIG及单TIG。在激光功率密度较大时,电压变异系数为单光束-TIGTIG双光束-TIG;在相同的焊接参数下,双光束激光-TIG复合焊的焊缝表面成形较单光束激光-TIG复合焊的均匀连续。 相似文献
2.
3.
利用小功率脉冲激光-TIG电弧复合焊在2mm厚度的不锈钢上进行堆焊,研究脉冲激光束(持续时间4 ms、峰值300 W、频率15 Hz)对电弧形态、熔池行为和焊缝成形的影响。结果表明,脉冲激光加入后,电弧中心高温区发生膨胀,并将电弧阳极斑点稳定在激光斑点处,TIG电压发生升高。当脉冲激光作用到熔池上时,熔池液态金属迅速向后方流动,熔池长度迅速增大;激光脉冲消失1ms后,熔池长度才开始逐渐减小,2 ms后液态金属向前回流,致使焊缝表面形成了鱼鳞纹,改善了焊缝表面成形。激光-TIG电弧复合焊的熔深是TIG焊的1.77倍,是激光焊熔深的2.6倍。而在相同熔深下,复合焊接速度比TIG焊提高了50%。 相似文献
4.
以8 mm厚的低碳钢为研究对象,在氧气的保护下,用小功率光纤激光在待焊焊件表面进行预熔处理,使表面熔化生成一层氧化层,然后用TIG焊或激光电弧复合焊覆盖氧化层,研究工艺参数对焊缝成形的影响.结果表明,激光预熔后进行覆盖焊接,电弧没有收缩,熔深增加到1.5倍左右,表面成形良好.随着电流的增加,熔深增加,但激光预熔后的焊道增加更快.随着焊接速度的增加,熔深减小.随着激光预熔功率的增加,熔深增加.随着复合焊接中激光功率的增加,熔深增加.焊缝含氧量的增加,使得表面张力温度系数由负变正,是低碳钢激光预熔活性焊接熔深增加的主要原因. 相似文献
5.
用激光-TIG复合热源对2.5 mm厚TA15钛合金进行对接焊试验.利用万能力学拉伸机、红外热成像仪、电子探针(EPMA)、扫描电镜(SEM)等分析手段对焊接接头进行测试分析,并与单TIG焊进行对比.分析焊接工艺参数和接头保护时间对焊接接头形貌和性能的影响.结果表明,实现2.5 mm厚钛合金全熔透焊接时,激光-TIG复合焊比单TIG焊速度更快、热输入更低,焊缝和热影响区更窄,晶粒更细;相同保护条件下,激光-TIG复合焊接头比单TIG焊接头具有更高的强度、塑性和更好的疲劳性能;激光-TIG复合焊缝冷却速率高于单TIG焊,获得良好的保护状态时所需保护时间更短. 相似文献
6.
7.
在活性焊接法研究的基础上提出了激光辅助TIG焊方法.焊前在氧气保护下采用小功率激光器熔化焊道表面,然后用常规TIG焊覆盖激光预熔焊道,从而可使熔深增加,熔宽减小.结果表明,激光预熔和未预熔焊道熔深、熔宽均随焊接电流的增加而增加,但激光预熔焊道熔深增加的更快;焊接速度的增加使激光预熔和未预熔焊道熔深、熔宽均减小;随激光功率增加,焊道熔深增加,熔宽减小;随预熔速度的增加,熔深先增大后减小,熔宽先减小后增大.综合最佳参数后可以得到焊缝熔深增加明显、焊缝表面成形良好的焊道,从而可以发展为一种新的活性焊接法. 相似文献
8.
《热加工工艺》2020,(7)
激光-等离子电弧复合焊接技术是具有良好工业前景的新型焊接技术,相比于TIG电弧,等离子电弧更加稳定,钨极烧损小,能显著提高焊接效率。以10 mm厚度的304不锈钢为母材进行表面堆焊,研究了激光功率、离焦量、焊接电流、焊接速度和热源间距对熔深、熔宽的影响。结果表明,复合焊的熔深熔宽大于单独焊的熔深熔宽,随着激光功率的增加,熔深熔宽逐渐增加。焊接电流小于200 A时,熔深的变化大于熔宽的变化,电流大于200 A时,二者的变化速度接近一致。熔深对离焦量敏感,负离焦能得到更大的熔深。随着焊接速度增大,熔深熔宽逐渐变小,高速下的焊接过程更加稳定。随着热源间距的增大,复合焊熔深逐渐变小,熔宽呈减小趋势,熔深变化较大。激光后置的焊接方式要优于激光前置。 相似文献
9.
10.
11.
《Science & Technology of Welding & Joining》2013,18(6):441-446
AbstractThe laser leading hybrid welding mode [laser tungsten inert gas (laser-TIG)] and TIG leading hybrid welding mode (TIG-laser) were utilised in the magnesium alloy welding process. The effects of TIG arc current and the distance between laser beam and TIG electrode (Dla) on penetration depth and melting efficiency in different hybrid welding modes were investigated. Results reveal that there is a decided difference in variation trend of penetration depth with Dla in different welding modes. The penetration depth increases first and then decreases with the Dla increasing from 1 to 7 mm in TIG-laser hybrid welding mode while the penetration depth decreases monotonously with Dla in laser-TIG hybrid welding mode. The increase percentage of melting efficiency remains at ~20% in laser-TIG hybrid welding mode while the increase percentage fluctuates acutely and achieves the maximal value (~53·14%) at the arc current of 120 A in TIG-laser hybrid welding mode. 相似文献
12.
An experiment for determining the laser-TIG hybrid welding characteristics was carried oat in three kinds of hybrid methods: CO2 laser-TIG coaxial hybrid, CO2 laser-TIG paraxial hybrid and Nd: YAG laser-TIG paraxial hybrid. The experimental results indicate that hybrid welding has two welding mechanisms in CO2 laser-TIG hybrid welding: deep penetration welding and heat conduction welding. As the effect of the laser-induced keyhole, the arc root is condensed, the current density and penetration depth increase significantly, the welding characteristic is apt to deep penetration welding.When current increases to some degree, the keyhole induced by laser disappears, which produces a shallow penetration and wide bead. The weld exhibits heat conduction welding characteristics. Furthermore, the arc images and weld bead crosssections of three kinds of hybrid manners were also compared and analyzed at different welding currents, which established the foundation for understanding the welding characteristics of laser-TIG hybrid welding comprehensively. 相似文献
13.
《Science & Technology of Welding & Joining》2013,18(4):403-411
AbstractThe experiments of CO2 laser TIG paraxial hybrid welding with 4 mm thick AISI 321 stainless steel sheet have been performed. The arc images and welding characteristics have been investigated with different energy ratios between laser and arc. The experimental results indicate that the hybrid welding is similar to laser welding and has also two welding mechanisms: deep penetration welding and heat conduction welding. Because of the effect of keyhole induced by laser, the arc root can be stabilised and compressed, and the current density and the penetration depth are all increased significantly, which show the characteristics of deep penetration welding. However, when the current is increased to a critical value, the laser induced keyhole disappears and the arc expands obviously, which decreases the penetration depth, so that the welding mechanism has been changed from deep penetration welding to heat conduction welding. Furthermore, the effects of distance between laser beam and electrode, pulsed laser and hybrid manners on hybrid welding characteristics have also been studied. 相似文献
14.
Makoto Doi 《Welding International》2013,27(3):188-196
To make progress in laser-arc hybrid welding, especially when applied to thick steel plate, it is essential to get the remarkable synergic effect of deep penetration. It is suggested that the effective process is combining hollow cathode TIG with high beam quality laser welding. Penetration of hollow TIG/YAG hybrid welding was investigated by numerical analysis. A keyhole surface model taking into account the laser beam parameter product (BPP) was developed. The calculated keyhole surface profiles of coaxial hybrid welding are wider and deeper than that of YAG laser welding alone. As a result, single-pass butt welding of 20 mm thickness steel plate was achieved under the conditions of BPP = 0.9 mm mrad at laser power 1.8 kW. To confirm numerical results, coaxial hybrid welding tests with a hollow cathode TIG was conducted. The welding penetration was about two times as deep as a YAG laser alone. It was found that coaxial hybrid welding with hollow TIG/YAG had a large synergic effect. 相似文献
15.
采用激光-TIG弧复合焊接工艺对钛合金T形结构单面焊背面双侧一次成形焊接新技术进行了研究,通过综合试验、对比分析等方法,研究了多种试验条件下T形结构焊缝成形特点及影响因素,给出了采用激光-TIG复合焊接工艺实现钛合金T形结构单面焊背面双侧一次成形焊接的最佳工艺方案.结果表明,采用激光-TIG复合焊接工艺焊接钛合金T形结构与钨极氩弧熔透焊工艺相比在焊缝组织、焊接效率、焊缝成形、间隙适应性等方面有明显的优势. 相似文献
16.
17.
0IntroductionRecently,laser-arc hybrid welding,as a rising spe-cial manufacture technology,has attracted more and moreinterest and attentions of some researchers and weldingcompanies.But,concerning laser-TIG hybrid welding,most of the research in this area mainly focused on contin-uous wave laser-TIG arc hybrid welding[1-3].In previousworks,because of the absorption and defocusing of laserenergy by hybrid arc plasma,the energy loss of laser wasvery serious when laser traversed arc in continu… 相似文献
18.
采用激光-TIG复合热源和TIG焊接异种金属镁和铝,利用X射线衍射仪、金相显微镜和扫描电镜研究镁和铝焊接接头的微观组织、元素分布。结果表明,TIG焊接镁和铝形成连续的金属间化合物层,导致镁和铝接触的界面开裂,不能实现有效的连接。激光-TIG复合热源由于其焊接速度高和对熔池的快速搅拌作用,使镁和铝形成的金属间化合物由连续的层状变成弥散的状态,改善了异种金属镁和铝的焊接性。镁和铝激光-TIG复合热源焊接的焊缝成形均匀,美观。 相似文献
19.
The influence of laser parameters on arc behavior of laser-TIG double-side welding was investigated by utilizing CCD sensor and image processing methods. It was found that arc images had an obvious transformation from laser preheating to laser plasma ejected from the keyhole bottom, resulting in the phenomena of arc column convergence and arc root constriction. The attraction phenomenon of the laser and the arc is also found in laser-TIG double-side welding. More noteworthy is that the behavior of arc attraction or constriction became much obvious at a lower current or laser plasma ejected from the keyhole bottom. The decrease in arc voltage had a certain relation with the improvement of arc stability. 相似文献