Structural considerations in friction welding of hybrid Al2O3-reinforced aluminum composites
(1. Busan Metropolitan City Hall, Fundamental Industries Division, 2001 Jungang-ro, Yeonje-gu,
Busan 611-735, Korea;
2. Department of Automotive & Mechanical Engineering, Silla University, San 1-1, Gwaebop-Dong,
Sasang-Gu, Busan 617-736, Korea;
3. Research & Development Center, Sam-Ho precision, 1256-1 Daejeo2-dong, Gangseo-gu,
Busan 618-807, Korea;
4. National Core Research Center for Hybrid Materials Solution, Pusan National University,
Busan 609-735, Korea)
Busan 611-735, Korea;
2. Department of Automotive & Mechanical Engineering, Silla University, San 1-1, Gwaebop-Dong,
Sasang-Gu, Busan 617-736, Korea;
3. Research & Development Center, Sam-Ho precision, 1256-1 Daejeo2-dong, Gangseo-gu,
Busan 618-807, Korea;
4. National Core Research Center for Hybrid Materials Solution, Pusan National University,
Busan 609-735, Korea)
Abstract: Comparative studies on the relationship between the welding parameters and joining efficiency in the friction welding of hybrid Al2O3-reinforced aluminum composites were conducted. Metal matrix composites (MMCs) with 37% (volume fraction) aluminum particle were joined by friction welding. The results show that the effects of the rotation speed on the reduction rate of particle size are greater than those of the upset pressure, and the area of the MMC weld zone decreases as the joining efficiency increases, while it is considered that the joining efficiency does not increase as the reduction rate of particle size decreases. During the macro-examination of the bonding interface, a gray discolored region was observed on the bonding interface, and the center of the region was dark gray. After the micro-examination of the bonding interface, base metal made some second particulate formed by condensed alumina particulate but discoloration part distributed minute alumina particulate without second particulate. Consequently, it was also observed that rotational speed of 3 000 r/min and upset pressure of 63.6 MPa showed a very good joint.
Key words: friction welding; hybrid aluminum composite; bonding interface; joining efficiency; metal matrix composite