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Advances in Manufacturing 2020年第1期8卷 59-71页

作者： M.Wasif Safeen P.Russo Spena G.Buffa D.Campanella A.Masnata l.fratini Faculty of Science and Technology Free University of Bozen-BolzanoBolzano 39100Italy Department of Management and Production Engineering Polytechnic University of TurinTorino 10129Italy Department of Engineering University of PalermoPalermo 90128Italy

Widespread use of aluminum alloys for the fabrication of car body parts is conditional to the use of appropriate welding methods,especially if dissimilar welding must be performed with automotive steel *** stir welding(FSW)is considered to be a reasonable solution to obtain sound aluminum-steel *** this context,this work studies the effects of tool position and force control in dissimilar friction stir welding of AA6061 aluminum alloy on DC05 low carbon steel in lap joint configuration,also assessing proper welding parameter *** eye and scanning electron microscopy(SEM)have been used to detect macroscopic and microscopic defects in joints,as well as to determine the type of intermixture between aluminum and *** joint strength of sound joints has been assessed by shear tension *** point out that tool force control allows for obtaining joints with better quality and strength in a wider range of process parameters.A process window has been determined for tool force conditions to have joints with adequate strength for automotive purposes.

关键词： AA6016 aluminum alloy Dissimilar materials DC05 low carbon steel Friction stir welding(FSW) Welding parameters

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确定管坯压胀形成形性能的简单实验方法

国外金属加工 2003年第4期24卷 28-32页

作者： l-Fllice l.fratini F.Micari 杨连发桂林电子工业学院机电与交通工程系，广西桂林541004

在管坯液压胀形工艺中，管坯放置于具有合理形状的模具内，靠管内液压使材料成形。在成形过程中，运动凸模促使材料轴向流动。本文提出了一个简单的实验方法，可进行各主要工艺参数对材料成形性能影响的大量的实验研究。此外，还采用了... 详细信息

在管坯液压胀形工艺中，管坯放置于具有合理形状的模具内，靠管内液压使材料成形。在成形过程中，运动凸模促使材料轴向流动。本文提出了一个简单的实验方法，可进行各主要工艺参数对材料成形性能影响的大量的实验研究。此外，还采用了基于有限元技术的数值分析及塑性破坏准则来预测胀裂缺陷的发生。

关键词：管坯液压胀形成形性能有限元数值分析塑性破坏准则冲压

Dual phase titanium alloy hot forging process design： experiments and numerical modeling

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Advances in Manufacturing 2015年第4期3卷 269-281页

作者： A. Ducato G. Buffa l. fratini R. Shivpuri Department of Chemical Management Computer and Mechanical Engineering University of Palermo Viale delle Scienze Palermo 90128 Italy Integrated Systems Engineering The Ohio State University 1971 Neil Ave Columbus OH 43210 USA

Titanium alloys materials when both good weight reduction are required are considered desirable mechanical properties and at the same time. This class of materials is widely used in those fields （aeronautics, aerospace） in which common steels and light-weight materials, e.g., aluminum alloys, are not able to satisfy all operative service conditions. During the last decade, forg- ing of titanium alloys has attracted greater attention from both industrial and scientific/academic researchers because of their potential in providing a near net shaped part with minimal need for machining. In this paper, a numerical model of the forging sequences for a Ti-6A1-4V titanium alloy aerospace component is presented. The model was tested and validated against experimental forgings. The model is then applied to predict loads final microstructure and defects of an aeronautical component. In addition to metal flow and die stresses, microstructural transformations （α and β phases） are considered for the determination of proper process parameters. It is found that transformation from α/β to β phase during forging and reverse transformations in post-forge cooling needs to be considered in the computational model for reasonable prediction of forging loads and product properties.

关键词： Finite element method (FEM) Ti-6Al-4V Hot forging Phase prediction

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Advances in Manufacturing 2016年第4期4卷 287-295页

作者： G. Buffa M. De lisi E. Sciortino l. fratini epartment of Chemical Management Computer and Mechanical Engineering University of Palermo Viale delle Scienze 90128 Palermo Italy

Dissimilar stir welding （FSW） lap joints were produced by friction out of Ti6A14V titanium alloy and AA2024 aluminum alloy sheets. The joints, welded with varying tool rotation and feed rate, were studied by ana- lyzing the maximum shear strength, Vickers microhardness and optical observations. A dedicated numerical model, able to take into account the presence of the two different alloys, was used to highlight the effects of the process parameters on temperature distribution, strain distribution, and material flow. The combined analysis of experimental measurements and numerical predictions allowed explaining the effects of tool rotation and feed rate on the material flow. It was found that tool rotation had a larger impact on the joint effectiveness with respect to feed rate. A competition between material mixing and heat input occurs with increasing tool rotation, resulting in higher joint strength when lower values of tool rotation are used.

关键词： Finite element method (FEM) Ti6A14V AA2024 Friction stir welding (FSW) lap joint