FSW搅拌摩擦焊接.pptVIP

静思笃行 持中秉正 　　　　　　　 秋记与你分享 我们毕业啦 其实是答辩的标题地方 Crew Instructor 奚家冰 Dr. Joseph P. Domblesky June 25th,2016 何钦江 王武强 Nanjin University of Aeronautics and Astronautics The Principle and Application of the Fricton Stir Welding CONTENTS The Principle Applications Features Summary The Principle The Principle Features Applications Summary Friction-stir welding?(FSW) is a solid-state joining process that uses a third body tool to join two facing surfaces. As described in the left picture,it consists of cylindrical-shouldered and a profiled probe.With the development of science and technology, The design of the tool has progressed. Original type tool design W-based tool Tri-Flute type tool PCBN tool The Principle Features Applications Summary . Fundamental Principle Heat is generated between the tool and material which leads to a very soft region near the FSW tool. It then mechanically intermixes the two pieces of metal at the place of the joint, then the softened metal can be joined using mechanical pressure (which is applied by the tool), much like joining clay, or dough. Features Features Applications Summary . The Principle The solid-state nature of FSW leads to several advantages over fusion welding methods without cooling from the liquid phase. It include: ★Good mechanical properties in the as-welded (熔接状态）condition; ★ Low environmental impact; ★ Lower cost that benefits from switching from fusion to friction; ★ Low environmental impact. Features Applications Summary . The Principle However, some disadvantages of the process have been identified: ★ Exit hole left when tool is withdrawn（撤出）. ★ Large forces required to hold the plates together,and the materials requires large stiffness. ★ Less flexible than manual processes (difficulties with thickness variations and non-linear welds). ★ Often slower moving rate than some fusion welding techniques, although this may be offset if fewer welding passes(焊道） are required. Applications Appl