tailieunhanh - WELDING PROCESSES_2

Despite the wide availability of literature on welding processes, a need exists to regularly update the engineering community on advancements in joining techniques of similar and dissimilar materials, in their numerical modeling, as well as in their sensing and control. In response to InTech's request to provide undergraduate and graduate students, welding engineers, and researchers with updates on recent achievements in welding, a group of 34 authors and co-authors from 14 countries representing five continents have joined to co-author this book on welding processes, free of charge to the reader. This book is divided into four sections: Laser Welding; Numerical. | Chapter 9 Principles and Thermo-Mechanical Model of Friction Stir Welding Jauhari Tahir Khairuddin Jamaluddin Abdullah Zuhailawati Hussain and Indra Putra Almanar Additional information is available at the end of the chapter http 50156 1. Introduction Friction stir welding FSW is a solid-state welding process that gained much attention in research areas as well as manufacturing industry since its introduction in 1991 1 2 . For almost 20 years FSW has been used in high technology applications such as aerospace to automotive till high precision application such as micro welding. The main feature of a solid-state welding process is the non-melting of the work material which allows a lower temperature and a lower heat input welding process relative to the melting point of materials being joined. This is advantageous over the conventional fusion welding where excessive high heat input is required to melt the work material. Much less heat input required for FSW translates into economic benefits safer and less complicated welding procedures. The friction stir welding make it possible to join light weight materials such as aluminium alloy magnesium alloy copper and titanium alloys which are very difficult to weld by conventional welding. These clear advantages have greatly increased the usage of these materials in structural applications 3 4 . In addition FSW also makes possible to produce sound weldment in 5000 and 7000 series aluminium alloys that are not possible to be welded using conventional method. FSW does not produce sparks or flames. Thus safety environmental and legislation issues are not of major concern. FSW process provides proven good quality and strong weldment with inexpensive and lesser number of equipment eliminates the use of filler metal and improved weldability. Due to these factors FSW has successfully been employed in aerospace automobile and ship building industries. The need to further understand and improve FSW process .