• 한국기계가공학회지
• /
• 제12권6호
• /
• pp.37-44
• /
• 2013

Friction stir welding (FSW) is a solid state joining technique that has expanded rapidly since its development in 1991 and has numerous applications in a wide variety of industries. This paper introduces the basic principles of friction stir welding (FSW) and presents a survey of the latest technologies and applications in the field. The basic principles that are discussed include the terminology, tool/workpiece processes, FSW merits and process variants. In particular, the process variants including the rotation speed and traveling speed are discussed, which include the defect-free zone in an oxygen free copper and Al alloy, respectively. Multiple aspects of the FSW machine are developed, including a horizontal 2D FSW machine and a hybrid complex FSW machine. The latest applications are introduced, with an emphasis on the recent advances in the aerospace, automotive, and IT display industries. Finally, the direction for future research and potential applications are examined.

• 한국생산제조학회지
• /
• 제22권4호
• /
• pp.700-707
• /
• 2013

Owing to high oil prices and environmental issues, the automobile industry has conducted considerable research and made large investments to manufacture a high-efficiency automobiles. In the case of automobile wheels in which a lightweight material is used to increase the fuel efficiency a mold is used to increase the production efficiency; however, the use of the molding method for this purpose is very expensive. Therefore an automobile wheel consists of two parts. In this study a two-piece automobile wheel is manufactured by the friction stir welding(FSW) of Al6061-T6 to reduce the manufacturing cost and process complexity. The FSW welding tool geometry and rotational speed, and the feed rate are key factors that significantly affect the weld strength. Therefore tensile tests were conducted on specimens produced using various welding conditions, and the optimal FSW welding conditions were applied to manufacture aluminum wheels. To ensure reliability, prototype aluminum wheels were manufactured and their mechanical reliability and safety were evaluated using a durability test, fatigue durability test, and impact test. Through this study, aluminum wheel production was made possible using the FSW method.

• Journal of Welding and Joining
• /
• 제33권2호
• /
• pp.8-13
• /
• 2015

This study was carried out to evaluate mechanical properties of the jointed Al6061/HT590 alloys by friction stir welding (FSW). FSW was conducted under the conditions with tool rotating speed of 500 RPM and traveling speed of 300 mm/min., where Ar gas was introduced to prevent the materials from corrosion during the welding process. Electron back-scattering diffraction (EBSD) was used to characterize microstructures such as grain size, misorientation angle and crystal orientation. Evolution of intermetallic compounds in Al6061 during the process were examined in terms of morphology, size and aspect ratio at three distinct zones Al base material, heat affected zone and stir zone, where transmission electron microscope (TEM) was used. It was revealed that FSW gave rise to refinement of grains as well as growth of intermetallic compounds in Al6061. The morphological changes of intermetallic compounds exerted an influence on mechanical properties, resulting in occurrence of fracture in the part of the base material instead of the jointed parts (heat affected zone and stir zone). This study systematically evaluated the microstructural evolutions during the FSW for joining Al6061 with HT590 and their effect on mechanical properties.

• 항공우주기술
• /
• 제11권2호
• /
• pp.33-38
• /
• 2012

지구 저궤도 위성은 발사체에서 분리된 이후 탑재 소프트웨어에 의해 자동으로 초기 동작을 수행한다. 이후 본체 초기 점검 기간 동안의 지상국 접속을 통해 정상 운용 모드로의 전환을 준비한다. 먼저 태양 전지판 전개 여부를 포함한 위성의 건강 상태를 확인한 이후 각 장치의 기능을 점검한다. 정상 운용 모드에 사용되는 모든 장치의 활성화가 완료된 이후 영상 촬영을 위한 기동 성능을 점검하며, 궤도 조정을 위한 기능을 점검한다. 초기 기능 점검은 한정된 지상국 교신 시간동안 수행되므로 사전에 모든 절차가 상세히 설계되어야 한다. 초기 점검 절차는 지상국 접속 시간에 따라 구분되어 수행된다. 또한 발생 가능한 모든 상황을 대비한 절차도 준비되어야 한다. 정상적인 점검 절차 수행 중에 발생할 수 있는 다양한 상황 및 예상치 못한 긴급 상황에 대한 조치 절차도 준비되어야 한다. 이러한 긴급 절차도 지상국 교신 시간을 고려해 설계된다. 저궤도 위성은 성공적으로 발사되었으며, 본체 초기 점검도 성공적으로 완료되었다. 이 논문에서는 저궤도 위성의 본체 초기 점검 설계 및 수행 결과에 대해 설명한다.

• Journal of Welding and Joining
• /
• 제31권1호
• /
• pp.33-37
• /
• 2013

Robotized MIG welding of large aluminium components for high speed trains is state-of-the-art. The implementation of online laser cameras enables seam tracking and adoptive modification of welding parameters. A constant fill is achieved regardless of the gap tolerances. Friction Stir Welding has been introduced to the market as a reliable and fast joining technology. The advantages of high welding speeds and the elimination of arc light, fumes and liquefaction in the welding spot lead to economical realisation of heavy-duty gantry systems. FSW robots offer a high flexibility with regard to welding of curved parts, and can be equipped with laser cameras for exact joint tracking.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
• /
• pp.522-527
• /
• 2002

The microstructure and mechanical properties of friction stir welded OFC plates with 2mm in thickness were examined with the changing welding parameters such as welding speed, rotation speed in this study. The sounding welding conditions was acquired at the optimum welding conditions of the 41mm/min to 61mm/min of welding speed at 1250 rpm of rotation speed. The microstructure of weld zone was divided into four parts such as the base metal region (EM), thermal mechanical affected zone (TMAZ), heat affected zone (HAZ), stir zone (SZ). The grain size in the SZ and the width of weld nugget were increased with increasing welding speed. The hardness profiles of the base metal were distributed about 80HV. The HAZ is a slightly softened region of about 60~75 HV relative to the base metal. The hardness profiles of the SZ were higher than that of base metal. The tensile strength was increased with increasing welding speed. In case increasing rotation speed, tensile strength was decreased. The maximum tensile strength was about 220:MPa which was 110% of joint efficience of that of base metal at 41mm/min of welding speed, 1250rpm of rotation speed.