搅拌摩擦焊清洁制造工艺过程中的缺陷分析（英文）

清洁生产是制造工艺过程中追求的目标。搅拌摩擦焊是一种比目前最好的传统焊接工艺更好、对环境损害更低的连接技术。搅拌摩擦焊工艺的能量效率高、无耗材、无损耗、无辐射。因此,它是一种能获得优质焊接接头的清洁焊接工艺。但它在焊接过程中会产生缺陷,为使其成为一种可靠的生产工艺,需要对其进行进一步优化。本文作者对搅拌摩擦焊接头的缺陷进行表征。结果表明,缺陷的产生是由于焊件过程的产生的热量不够、搅拌针附近的物质移动不充分、搅拌针后部的材料致密化不够。焊接过程中产生的热量和物料的搅拌程度取决于搅拌摩擦焊的焊接参数。焊接参数选择不当,可导致缺陷的产生。本文所得结果来源于文献和实验。根据各种缺陷的特征,如其可能产生的位置、减少缺陷产生的主要参数等,提出了减少缺陷产生的一些措施。

铝-铜搅拌摩擦焊综述（英文）

在工程应用中需要通过连接不同的材料制成零部件以满足不同的要求。由于所用材料的力学、热和电性能存在巨大差异,使得这些零部件的制造极具挑战性。搅拌摩擦焊(FSW)能够用于连接异种材料,如铝(Al)和铜(Cu)。关于异种材料的连接,特别是铝-铜,文献来源比较分散,因此,铝-铜搅拌摩擦焊的信息收集比较繁琐。本文综述铝-铜的搅拌摩擦焊,为科研人员提供相关信息。文中全面涵盖和系统总结铝-铜搅拌摩擦焊的各项问题,如工具设计和尺寸、工艺参数以及流程对零件力学性能、微观组织和缺陷形成的影响。此外,还提出和探讨铝-铜搅拌摩擦焊的几个改进工艺。该工作不仅列举前人的主要成果,还提出铝-铜搅拌摩擦焊的发展建议。

水下搅拌摩擦焊接:一种具有改善接头性能巨大潜力的搅拌摩擦焊接新方法（英文）

搅拌摩擦焊接(FSW)是一种固态焊接方法,它能够焊接普通熔焊过程难以焊接的材料;且与熔焊相比,具有高效节能和环境友好的特点。尽管FSW与熔焊相比有更多的优点,但是FSW过程中的热循环会溶解或者粗化热处理铝合金中的沉淀强化相,使接头软化,从而导致其力学性能下降。水下搅拌摩擦焊接(UFSW)是一种可以克服这些缺陷的方法。这种方法适合于在焊接过程中对热敏感的合金,且已广泛用于热处理铝合金。本文对UFSW的研究现状和发展提供了全面的文献综述。与FSW进行对比,从不同角度讨论和总结UFSW的重要性;并对材料流动、温度变化、工艺参数、显微组织和力学性能等基本原理进行详细阐述。结果表明,与FSW相比,UFSW是一种可以改善接头强度的新方法。

Effect of varying spatial orientations on build time requirements for FDM process: A case study

In this research, effect of varying spatial orientations on the build time requirements for fused deposition modelling process is studied. Constructive solid geometry cylindrical primitive is taken as work piece and modeling is accomplished for it. Response surface methodology is used to design the experiments and obtain statistical models for build time requirements corresponding to different orientations of the given primitive in modeller build volume. Contour width, air gap, slice height, raster width, raster angle and angle of orientation are treated as process parameters. Percentage contribution of individual process parameter is found to change for build time corresponding to different spatial orientations. Also, the average of build time requirement changes with spatial orientation. This paper attempts to clearly discuss and describe the observations with an aim to develop a clear understanding of effect of spatial variations on the build time for Fused Deposition Modelling process. This work is an integral part of process layout optimization and these results can effectively aid designers specially while tackling nesting issues.

Effect of tool plunge depth on reinforcement particles distribution in surface composite fabrication via friction stir processing

Aluminium matrix surface composites are gaining alluring role especially in aerospace, defence, and marine industries. Friction stir processing(FSP) is a promising novel solid state technique for surface composites fabrication. In this study, AA6061/SiC surface composites were fabricated and the effect of tool plunge depth on pattern of reinforcement particles dispersion in metal matrix was investigated. Six varying tool plunge depths were chosen at constant levels of shoulder diameter and tool tilt angle to observe the exclusive effect of plunge variation. Process parameters chosen for the experimentation are speed of rotation, travel speed and tool tilt angle which were taken as 1400 rpm, 40 mm/min, and 2.5 °respectively. Macro and the microstructural study were performed using stereo zoom and optical microscope respectively. Results reflected that lower plunge depth levels lead to insufficient heat generation and cavity formation towards the stir zone center. On the other hand, higher levels of plunge depth result in ejection of reinforcement particles and even sticking of material to tool shoulder. Thus, an optimal plunge depth is needed in developing defect free surface composites.

Effect of wire tension on different output responses during wire electric discharge machining on AISI 304 stainless steel

WEDM is used in machining conductive materials where it is required to obtained complicated and intricate shapes with high accuracy.Various applications are in the field of automobile,medical industries,aerospace etc.WEDM is an economical machining option with short product development cycle.Surface roughness,kerf width,Material removal rate,Recast layer hardness and surface microhardness in WEDM are most important responses.In this paper,effect of varied Wire tension on SR,KW,MRR,RCL hardness and surface microhardness on AISI 304 have been investigated.Pulse on time,pulse off time,current and dielectric fluid are taken as fixed parameter.Results show that Wire tension influences the SR,MRR and Surface microhardness and has no effect on kerf width in case of Stainless steel304.

Multiple Response Optimization of Dimensional Accuracy of Nimonic Alloy Miniature Gear Machined on Wire Edm Using Entropy Topsis Andpareto Anova

The purpose of this research is to obtain the optimum cutting parameters to achieve the dimensional accuracy of Nimonic alloy miniature gear manufactured using Wire EDM.The cutting parameters investigated in this study are current,pulse on time(PON),pulse off time(POFF),wire tension(WT)and dielectric fluids.Ethylene glycol,nanopowder of alumina and oxygen are mixed to demineralized water to prepare novel dielectric fluids.Deviation in inner diameter,deviation in outer diameter,deviation in land and deviation in tooth width are considered to check the dimensional accuracy.Taguchi L_(16) is employed for experimental design and multiple response optimization is performed using Entropy TOPSIS and Pareto ANOVA.Results indicate that pulse on time is the most notable parameter for good dimensional accuracy followed by dielectric fluid,current,pulse off time and wire tension.Ethylene glycol mixed demineralized water is preferred for low dimensional deviation.The optimum WEDM parameters are pulse on time at 20μs,Ethylene glycol mixed demineralized water dielectric fluid,current at 3 A,pulse off time at 4μs,and wire tension at 18 N.