Influence of Heat Input on Microstructure and Mechanical Properties of Laser Welding GH4169 Bolt Assembly—Numerical and Experimental Analysis

By conducting the numerical and experimental analysis, the influence of heat input on the microstructures and mechanical properties of laser welding GH4169 bolt assembly is systematically investigated. The weld formation, temperature field, and residual stress distribution during laser welding by using the finite element modeling are consistent with experimental results. The numerical simulation results show that the increase of heat input imparts lower residual stresses and higher temperature gradient. During the process of laser welding, the steepest temperature gradient and the peak residual stress arise in the fusion zone (FZ). In addition, the dissolution of γ″ and γ′ toward the fusion line increases in heat affected zone (HAZ), but only Laves phase is observed in FZ. With increasing heat input from 24 to 48 J mm⁻¹, the ultimate tensile strength of welded joints decreases. Both the lowest microhardness values and tensile failure of GH4169 alloy laser welded joint are in FZ. Herein, it is that the relationship among the heat input, microstructures, and mechanical properties of GH4196 bolt assembly in laser welding is systematically established, which will be of guiding significance for the selection of welding parameters in aerospace.     

闪光焊机液压伺服系统故障诊断的研究

为了提高闪光焊机液压伺服系统故障诊断的准确性、实时性,在对液压伺服故障机理分析的基础上,运用计算机技术、数字信号处理技术、模糊故障诊断理论,设计出焊机液压故障诊断系统.对液压伺服系统模糊故障诊断算法进行了研究,并将其应用到焊机液压故障诊断系统.实际故障诊断结果表明,故障诊断系统能准确判断出液压伺服系统的故障部位、故障类...     

一种新型的加固计算机箱设计

介绍了一种新型加固计算机机箱,其独特的双层箱体结构,使它适合在各种复杂恶劣的环境条件下使用。通过设计实践,阐述了该箱体的结构特点和密封、隔振缓冲、电磁兼容等方面的具体解决方法,特别是箱体成型和综合热设计等关键技术。经环境试验和工程实际应用的检验,证明其具有较好的综合防护性能。     

Development of a mobile robotic system for working in the double-hulled structure of a ship

Shipbuilding processes involve highly dangerous manual welding operations. Welding ship walls inside double-hulled structures presents a particularly hazardous environment for workers. This paper describes the “Rail Runner X” (RRX), a new robotic system that can move autonomously inside the walls of a double-hulled ship and automatically execute the required welding processes. The RRX robotic system is composed of a mobile platform and a welding robot consisting of a 3P3R serial manipulator. The robot is used to weld U-shaped trajectories located between two longitudinal stiffeners. The mobile platform enables traverse movements onto neighboring longitudinal stiffeners. The entire cross section of the robotic system is small enough to be placed inside the double-hulled structure via a conventional access hole from the outside shipyard floor. The overall engineering design process that led to the final robot solution developed is presented in this paper, including kinematic analysis data and experimental results for verifying the autonomous movement and welding performance.     

TO焦距测试与自动激光焊接系统

在分析BOSA器件结构的基础上,提出一种基于图像分析的TO焦距测试与自动激光焊接方案. TO由气缸驱动从初始点向上单步移动,通过图像系统采集光斑图像,并基于OpenCV分析,通过比较分析结果,得到期望的TO位置.移动T0使焦点落在插芯与圆方管体的贴合面,并在此处进行激光焊接.实验表明,该系统具有良好的准确性和实用性.     

CO_2弧焊机器人电弧电压及焊接电流的智能控制

研制了一种以可编程控制器为核心器件 ,通过软件方式实现 CO2 弧焊机器人电弧电压及焊接电流合理匹配的智能控制系统 .系统通过具有修正因子自寻优功能的自组织模糊控制器维持所选定的焊接电流不变 .同时 ,系统针对 CO2 焊的短路、半短路和细颗粒过渡焊的电弧电压采取不同的自寻优目标和寻优方式进行寻优 .寻优后的电弧电压与焊接电流形成合理匹配 ,达到了稳定熔滴过渡过程 ,减少飞溅 ,改善成形的目的     

弧焊视觉轨迹控制中的自动导引方法研究

本文给出了采用三维视觉焊缝跟踪传感器实现机器人自主寻找焊缝、跟踪焊接、结束焊接的控制方法 ,实验表明该方法能够进一步提高焊接自动化水平     

蛋氨酸生产闪蒸工况角型阀门的研制

介绍了目前国内饲料级蛋氨酸生产项目闪蒸工况使用的角阀的现状,重点介绍了研制过程中如何针对实际应用过程中出现的问题进行的改进设计,结合自身切实经验,分别从阀门结构设计、内件材料选择、密封件材质选择和角阀零件的机加工工艺等方面,论述了闪蒸工况下角型阀门的特点以及加工过程中能够提高加工精度所需注意的问题,这些特点以及加工注意事项能够较好的保证该类型角阀能够适应饲料级蛋氨酸生产中的闪蒸工况要求。     

SiC颗粒增强铝基复合材料的真空电子束焊接

针对SiCp/6061Al型复合材料进行了真空电子束焊接的初步探讨.试验结果表明:电子束电流越大,熔深越深;焊接速度越快,熔深越小;焊接过程中SiC颗粒会与液态铝发生界面反应,生成脆相Al4C3;镁元素的气化易导致焊缝气孔的生成.     

铝-钢爆炸焊接试验与分析

介绍了一种铝-钢复合板爆炸焊接工艺，包括所采用的炸药、复合板的性能和爆炸焊接材料的准备等。采用了金相技术、电子探钳和电子显微镜物相鉴定手段以及力学性能分析．结果显示．该复合板的结合区存在着金属强烈的塑性变形、熔化和原子间的相互扩散等冶金过程；铝-钢复合板是一种具有特殊使用性能的新型结构材料．具有很高的经济效益和广泛的应用前景。