大型发动机缸体振击除芯工艺应用

描述了大缸径发动机振击除芯设备应用柔性设计、精益生产、绿色制造等理念的设计过程,实现一机多用、高效生产、绿色制造的过程。振击除芯设备实际应用过程中工装设计采用瓦口进行定位,通过2K全因子实验、响应曲面法确定振击除芯参数。铸件经振击除芯后铸件外表面及缸孔内部铸砂明显脱落,振击除芯效果明显。     

"田口方法"在吸波涂料中的应用

应用"田口方法"的优化设计思想,针对吸波涂料柔韧性差、附着力低的不足及其特点.通过系统设计及参数设计详细地介绍了"田口方法"在吸波涂料中的应用,通过大量实验研制了一种柔韧性好、附着力高的吸波涂料.     

DOE在高频电流感应钎焊焊接工艺参数优化中的应用

针对微钻头棒料因钨钢规格缩小,导致钎焊过程中出现钎焊强度降低的问题,对钎焊断面元素成分进行了分析,以提升钎焊棒材的抗剪强度为指标,运用试验设计正交分析法对高频电流感应钎焊过程中各工艺参数进行了计算和分析,对钎焊参数进行优化。     

田口方法在优化铝熔炼炉工艺参数中的应用

为提升铝熔炼炉热效率、降低污染物排放和提高熔体质量,根据影响熔炼性能的特性要因,运用正交表安排数值模拟方案,通过田口方法进行铝熔炼炉的工艺参数优化,得到最优的铝熔炼炉工艺参数组合,并对最优参数进行验证,结果表明达到了节源减排的目的.     

响应曲面法在大气等离子喷涂工艺研究中的应用

将响应曲面法应用于大气等离子喷涂Cr2O3涂层的工艺研究中,对喷涂电流、等离子气体成分和喷距等因素的显著性及交互作用的影响程度进行了分析,给出了涂层沉积厚度的拟合数学模型。研究表明,响应曲面法弥补了传统单变量和全因子优化实验的不足,可以运用到热喷涂领域的实验设计和数据分析中。     

基于QFD、TRIZ和DOE的DFSS集成模式研究

在六西格玛设计中,如何将顾客需求转化为可量化的设计特性是一个良好设计所必须具备的重要特征,而QFD、TR IZ和DOE等都是进行六西格玛设计的重要方支撑工具。在文中首先介绍了QFD、TR IZ和DOE的基础知识,然后对QFD与TR IZ、QFD与DOE的集成的可能性进行了探讨,并提出了TR IZ/DOE/QFD集成框架,最后通过结论对文章进行总结。     

基于响应面法的6013铝合金单模光纤激光焊接工艺及性能研究

选用2?mm 6013铝合金板材进行单模光纤激光焊接工艺试验,构建以激光功率、焊接速度、离焦量为输入变量,正背熔宽、背宽比和熔合区截面积为输出变量的3D响应面模型,模型具备显著性,且拟合良好.分析工艺参数变化对焊接接头几何特征的影响规律,并对典型焊缝进行了显微组织及力学性能分析.结果表明,激光功率与背面熔宽、背宽比及熔合区截面积变化呈正相关;焊接速度与输出变量均呈负相关;离焦量与正面熔宽及熔合区截面积变化呈正相关,与背宽比变化呈负相关.在背宽比回归模型中,激光功率与离焦量存在明显的交互作用.单模光纤激光可在低功率、高焊速的工艺匹配下实现2?mm 6013铝合金全熔透,且焊接接头截面熔宽更窄,微观晶粒尺寸小,其抗拉强度和断面延伸率分别为315.5?MPa和12.3％,可达到母材的90％和42％.     

基于响应曲面法的衬套强力旋压工艺参数优化设计

连杆衬套大多采用强力旋压成形工艺,其工艺参数多而复杂,而且工艺参数耦合在一起影响着连杆衬套的力学性能。为了揭示工艺参数对连杆衬套力学性能的影响规律,应用Design-Expert 8.0软件对连杆衬套强力旋压成形工艺进行数值模拟,基于响应曲面设计法对连杆衬套在强力旋压成形中的减薄率、进给比和热处理温度3个主要工艺参数进行优化设计。将经过强力旋压后的连杆衬套抗拉强度作为优化目标响应值,采用三元二次回归方程作为软件分析的数学模型。试验数据及软件分析结果表明,当抗拉强度在605~645 MPa时连杆衬套的力学性能均能满足产品图纸要求。连杆衬套强力旋压工艺参数的优化组合为:减薄率30%、进给比0.3 mm·r-1、热处理温度275℃。     

反向方法在板料成形工艺设计中的应用研究

利用结合拉延筋计算的反向方法的数值模拟技术，研究了其在板料成形工艺设计中的应用，提出了进行初期工艺设计评估的新方法。同时对后轮毂鼓包内板件毛坯进行工艺设计，与福特公司的ＭＴＬＦＲＭ软件的对比结果表明设计的工艺是合理的，也表明该方法可以适用于大型覆盖件的工艺设计。     

焊接工艺在矿车轮中的应用

本文主要阐述矿车轮磨损后无法投入使用,通过实施手工电弧焊进行焊接修复,恢复矿车轮的使用功能。此方法适用于井下各型号的矿车轮的修复,可以延长矿车轮的使用寿命,提高设备台效。     

Mechanical vibrations in welding processes

This article presents the current state of knowledge on the issue of supporting classic welding processes by mechanical vibrations. Selected results of own research on the impact of mechanical vibration on the structure and properties of welding structures are also discussed.     

Optimization of ironing processes by means of DOE and FEA

The range of possible applications of ironing processes reaches from the production of cylindrical pressure tanks, shock absorber pipes, battery and beverage cans to the production of flacons for the cosmetics industry. One goal of the finite element analyses of ironing processes is to gain knowledge about process limits regarding maximized forming capacity and optimized surface quality. The ironing process is characterized by parameters like friction, geometry of the ironing ring and anisotropic material behavior. Due to the high complexity of this process, it is complicated to detect these effects on the basis of experimental investigations only. Therefore, one of the aims of this study is to identify relevant process parameters by means of systematic numerical analyses. The design of experiments was utilized to create a model of the ironing process. By means of this model it was possible to reduce the punch load and to minimize the tensile stresses in the first stage of the analyzed ironing process.     

Computer control of welding processes

Synopsis

Pressure vessels such as hydrocracking reactors are fabricated from 2.25 Cr‐1 Mo steel weld‐clad with austenitic stainless steel. In these reactors, hydrogen diffuses into the steels and can cause disbonding of the weld cladding after shut‐down and cooling to ambient temperature.

This type of cracking can develop when the following three conditions are fulfilled: a) high localised concentrations of hydrogen; b) high tensile residual stresses; and c) the presence of a sensitive structure.

The aim of this study is to clarify the influence of hydrogen diffusion on disbonding phenomena. A model was developed for calculating hydrogen distribution in steel claddings. The results were compared with hydrogen measurements and corroborated the theoretical model. The model can be used to predict or clarify the behaviour of the weld cladding with a view to preventing disbonding phenomena.     

Integral self-regulation in arc welding processes

As a result of the development of processes of gas-shielded consumable electrode arc welding with a constant electrode wire feed rate, characterized by different mechanisms of electrode metal transfer and large changes in the arc power with time, this study is carried out to supplement and generalize the concept of self-regulation of different arc welding processes.     

Temperature measurement problems in welding processes

This study examined development of the stir zone and plastic flow of the material during friction stir spot joining of aluminium alloys. The development of the stir zone was discussed through the observation of macro sections of the joints produced at various process times. The friction stir spot joining trial with insert of Au foil to lap surface and the dissimilar lap friction stir spot joining showed that the movement of the lap surface was attributed to the downward plastic flow from the upper plate to the lower plate around the probe. Additionally, it was clarified that the direction of the plastic flow was roughly the same as the direction of the tool rotation. The dissimilar butt friction stir spot joining suggested that the plastic flow occurred not only within the stir zone but also in a larger area below the tool shoulder. The present study revealed that the threads on the probe surface were important for producing the plastic flow of thickness direction during friction stir spot joining.     

Application of fused visual and thermal images in monitoring and evaluation of welding processes

This article presents the application results of different methods of merging images recorded using vision cameras and thermal imaging cameras. The images were recorded during the evaluation of a welding process. The object of observation was the welding arc and the welded joint during its cooling phase. Images recorded during GMA welding on two different welding stations have been taken into account. The observations have been conducted using cameras equipped with different optics systems. This article presents an analysis of the influence of different parameters of the optics systems on the resulting fused images. The analysis also considers the pre-processing method to ensure correct matching of images. The study shows that the fused image contains aggregated information useful in online monitoring and quality evaluation of the welding process.     

熔焊过程的热效率

介绍了电弧焊过程热效率的物理含义及熔焊过程热效率的研究概况，比较了不同熔焊过程的热效率，分析了焊接方法、焊接参数及母材成分与性能对熔焊过程的电弧热效率、熔化效率及焊接热输入的影响规律。分析了电弧热效率和熔化效率之间的关系，给出了常用熔焊方法热效率的试验值与推荐值，并对电弧热效率和熔化效率进行了定量描述。通过对熔焊过程热效率研究工作的总结分析，为研究人员提供了可靠的熔焊过程热效率指导性数据与经验公式。