共查询到19条相似文献,搜索用时 62 毫秒
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用Nd:YAG激光焊接殷钢薄板材料 总被引:3,自引:2,他引:1
用Nd:YAG脉冲激光作为焊接热源,对殷钢材料Invar36分别进行了平板单道焊接试验和对焊试验,分析了工艺参数(激光功率、焊接速度、脉冲宽度和离焦量)变化对焊缝的表面形貌、熔宽以及熔透性的影响.检测了0.85 mm厚的殷钢薄板对焊接头的硬度、成分以及拉伸强度.结果表明:激光功率和脉宽是影响焊缝熔深、熔宽和热影响区面积的主要因素;扫描速度对焊缝表面的鱼鳞状条纹间距影响尤为明显;离焦量主要影响焊缝的宽度和熔透性;合理匹配工艺参数能够实现0.85 mm厚度薄板的对焊,并且获得形貌良好的焊缝.焊缝的组织成分没有发生明显变化,拉伸强度和基体强度相当,显微硬度略低于基体硬度. 相似文献
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分析了铝合金激光焊接的工艺特性、技术难点和解决办法,阐述了多光束YAG激光焊接铝合金薄板的可能性,构建了多光束YAG激光焊接光路,解决铝合金薄板激光焊接过程的部分缺陷。如果合理使用保护气体并设置恰当的工艺参数,有可能解决铝合金薄板的YAG激光焊接难题,对其应用前景提出展望。 相似文献
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大功率Nd:YAG激光焊接过程同轴视觉传感 总被引:5,自引:0,他引:5
利用半透半反分光镜片成功地解决了激光焊接同轴视觉传感技术中同轴成像光信号分离提取难的问题,建立了大功率Nd:YAG激光焊接过程同轴视觉传感系统。针对无辅助照明光的激光焊接同轴视觉图像成像信号的特点,设计了相应的中值滤波和同态滤波来消除图像的低频噪声和增强图像,并基于图像阈值分割技术搜索、检测出了熔池和小孔图像边缘的位置。最后,利用Hough变换对图像边缘进行曲线拟合得到熔池和小孔边缘曲线的拟合方程并从拟合结果中求得熔池和小孔的二维尺寸。 相似文献
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介绍激光焊接工艺在目前汽车座椅骨架制造中的几种运用方式和相关的激光焊接设备。通过普通焊接工艺和激光焊接工艺的对比,阐明了激光焊接的优势。 相似文献
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介绍激光焊接工艺在目前汽车座椅骨架制造中的几种运用方式和相关的激光焊接设备.通过普通焊接工艺和激光焊接工艺的对比,阐明了激光焊接的优势. 相似文献
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钛合金材料激光焊接试验研究 总被引:1,自引:2,他引:1
针对TC4钛合金,采用激光焊接方法,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标GB3233—87Ⅱ级要求,实现了TC4钛合金的精密焊接。此外,还讨论了激光焊接的工艺因素对焊接质量的影响。 相似文献
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对数控YAG脉冲激光焊接机的原理和加工工艺进行了介绍,在工程实践中,依据数控YAG脉冲激光焊接机的理论分析,根据加工产品的具体参数,设计出相应的加工工艺图形和加工参数。可完成精确的产品焊接。 相似文献
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IL-Young Chung Jae-Do Kim Kyung-Ho Kang 《International Journal of Precision Engineering and Manufacturing》2009,10(2):11-16
Drilling a hole in Invar alloy is accomplished by using a nanosecond pulsed Nd:YAG laser. However, this process has a few
problems, such as heat effect and poor edge quality. Therefore, the ablation properties of the Invar alloy were investigated
by using an ultrashort pulsed laser, which is a regenerative amplifier Ti:sapphire laser with a 1 kHz repetition rate, a 184
fs pulse duration, and a 785 nm wavelength. To study the ablation characteristics of the Invar alloy, we measured the ablation
shape, width, and ablated depth at the energy fluence of a single pulse. The optimal condition for hole drilling is a z-axis
transfer depth of 4 μm, a circular feed rate of 0.2 mm/s, and a pulse energy of 26.4 μJ. A fine circular hole without burrs
and thermal damage were obtained under the optimal processing conditions. The ultrashort pulsed laser system is an excellent
tool for micro-hole drilling in Invar alloys without heat effects and poor edge quality. 相似文献
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A wide range of pulsed laser welding parameters was identified. These include average peak power density (APPD), peak power,
mean laser power, traverse speed, pulse repetition rate, duty cycle, pulse energy, spot size, and pulse duration. The type
of laser beam temporal pulse shape studied was a rectangular power pulse.
The effects of pulsed laser welding parameters on heat flow, weld dimension, and weldability are investigated. The study shows
that weld quality is principally affected by APPD, mean power, and traverse speed, of which APPD is the most critical process
parameter. A processing map containing the APPD effects is constructed as a guide for producing good welds. 相似文献
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ZHOU Zhenggan NI Xiansheng WEN Xiongwei LI Luming Institute for Nondestructive Testing Mechatronics Engineering Beihang University Beijing China Tsinghua Space Center Tsinghua University Beijing China Received March revised February accepted March published electronically November 《机械工程学报(英文版)》2011,(6):1103-1110
It is difficult to weld the material and structure of implantable neuro-stimulator such as pure medical titanium and irregular outside shield by conventional arc welding methods.Currently there are few reports on the neuro stimulator sealing technology,and none of them have simultaneously considered the quality control methods.In order to develop the sealing procedure and quality control methods,an investigation of applying Nd:YAG laser welding to implantable neuro-stimulator components is carried out.Firstly,the automatic Nd:YAG laser welding system equipped with proper fixture configuration is introduced.A special fixture structure is illustrated and the key point for the device is to reduce the fit-up gap between the two shields.Then,a novel welding process technique is proposed to satisfy the engineering requirements.The optimized process parameters for titanium shell,feedthrough and fastener are provided and concluded by an orthogonal experiment.Finally,different quality control measures such as visual inspection,X-ray detecting and leakage testing,are presented on the final products.The results show that the Nd:YAG laser welding applied on the implanted neuro-stimulator under optimized parameters can prevent welding defects and improve the weld joints quality.Combination of various quality control methods will guarantee the sealing performance and mechanical properties of the products.It is confirmed that the processing procedure and quality methods can not only resolve the process technology on welding ultra-thin structure of medical device,but also provide the reference for other implantable device. 相似文献
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在声光调Q二级管泵浦固体光源(DPSS)Nd:YAG激光器基础上,采用“单脉冲同点间隔多次”激光微加工工艺,对灰铸铁材料进行表面微造型加工。试验研究表面,该工艺能克服热效应产生的不良影响,有效防止金属熔融和重铸现象。通过选择合适的脉冲次数、激光波长以及辅助气体工艺,可获得较理想的微腔形貌和表面质量。采用JXA-840A分析了微加工形貌,表明微腔(槽)表面留有一层致密的硬化层,且与基体结合良好。通过对CA6DF2-26型柴油机激光珩磨缸套的性能试验,表明与普通平顶珩磨相比,柴油机机油耗降低53%,漏气量降低33%-50%。 相似文献
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提出了通过视觉传感获取焊接过程中的焊接特征信息并利用神经网络模型预测焊缝背面宽度的方法。利用大功率盘形激光器焊接了低碳钢SS400焊件,在焊接过程中改变焊接功率、焊接速度和焊接路径,并利用两台高速摄像机同步获取焊件正面和侧面出现的焊接特征信息。对获取的图像进行色彩空间转换、分层、滤波去噪和空域图像处理,提取飞溅、熔池和金属蒸气等焊接特征信息,观察焊接路径对各个特征的影响。最后,建立了一个三层的LMBP(LevenbergMarquardt Back Propagation)神经网络模型,将提取的特征信息作为输入量,预测焊缝的背面宽度。结果显示:当熔透不稳定或出现未熔透状态时,LMBP神经网络拟合度大于0.83,最大训练误差均值为0.002 8mm,最大实际误差均值为0.225 6mm。试验结果表明所建立的预测模型具有良好的准确性和稳定性。 相似文献
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脉冲激光焊接Hastelloy C-276合金的熔池流动传热特性分析 总被引:2,自引:2,他引:0
基于流体动力学方程和传热方程建立了三维瞬态模型,用于研究脉冲激光焊接0.5 mm厚Hastelloy薄板时熔池的流动行为及传热特性.应用Fluent软件,采用有限容积法(FVM)求解控制方程,用SIMPLE算法处理速度与压力的耦合.引入Pe来衡量焊接熔池中对流传热与传导传热的相对强弱,并以此分析焊接熔池的传热特性.结果表明:沿焊接方向,焊接熔池的流动速度随着离熔池中心距离的增加先增加后减小;在给定试验条件下,熔池流动速度在离熔池中心0.2 mm左右时出现最大值,且沿焊接方向前方稍大于后方,而后迅速减小为零;焊接熔池中对流的存在使得焊接熔池熔深较小而熔宽较大;最终的焊接形貌由对流传热与传导传热相互作用而成.对焊缝形貌的数值模拟结果与实验结果进行了比较,计算结果与实验结果吻合较好.此模型可为脉冲激光焊接Hastelloy C-276薄板时熔池流体流动行为的分析提供理论依据. 相似文献
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对0.6mm芯径3m长光纤输出100W连续Nd:YAG激光的光纤耦合效率进行了实验分析。围绕光纤耦合效率相关的量:激光模式、发散角、数值孔径、焦斑直径、精密光纤耦合器等问题进行了讨论;并给出实验结果:3m长光纤输出0~100W激光耦合效率典型值≥87%,最佳值为90%. 相似文献
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Bekir Sami Yilbas Sohail Akthar 《The International Journal of Advanced Manufacturing Technology》2011,56(1-4):115-124
Laser welding of Haynes 188 alloy sheets is carried out. Temperature and stress fields developed in the welding section are predicted numerically incorporating the finite element algorithm. The microstructural changes in the welding region are examined using the optical and electron scanning microscopes. The microhardness variation across the weld zone is measured and associated with the residual stress formed in this region. It is found that the microhardness follows the residual stress distribution in the weld core. The maximum residual stress is less than the elastic limit of the substrate material. 相似文献