Microstructure and Mechanical Properties of Ultrahigh‐Speed Friction‐Stir‐Welded Joints of In Situ Al₃Zr Particle‐Reinforced Aluminum Matrix Composite Sheets

Abstract

Herein, in situ Al3Zr + 6082Al aluminum matrix composite sheets subjected to ultrahigh‐speed friction stir welding (FSW) at welding and stirring‐head rotation speeds of 200 mm min−1 and 11 000, 13 000, or 15 000 rpm, respectively, are focused on. X‐ray diffraction, electron microscopy, energy‐dispersive spectrometry, microhardness testing, and tensile testing are used to investigate the microstructures and mechanical properties of the welds. The weld nugget zone (NZ) of the high‐speed FSW joint of the Al3Zr + 6082Al matrix composite sheet comprises mainly equiaxed recrystallized grains, the thermomechanically affected zone comprises equiaxed recrystallized grains and elongated plastically deformed grains, and the heat‐affected zone comprises recrystallized grains. Results show that the FSW joint formed at 13 000 rpm and 200 mm min−1 is extremely well formed and has a compact and uniform structure. The microhardness of the 13 000 rpm FSW joint is highest at an NZ hardness and tensile strength of 128.08 HV and 153.7 MPa (87% of that of the base metal), respectively.

Study on Microstructure and Mechanical Properties of Friction Stir Welding Joints of In-Situ Al3Zr/AA6082 Particle-Reinforced Aluminum Matrix Composites

“…aluminum matrix composites have good conductivity and corrosion resistance, high specific modulus and specific strength, which are often used as structural materials for aerospace, high-speed rail and automotive industries with great demand for lightweight materials [1][2][3][4][5][6][7][8]. the melting point, thermal conductivity and linear expansion coefficient of the reinforced phase in the composites are greatly different from those of the matrix aluminum alloy, which makes the welding performance of the aluminum matrix composites very poor and the weld is easy to form holes and inclusions.…”

Novel AA7075/AA2124-SiC-17p laminated structures for aerospace applications: A Comparative study into the mechanical performance of PA6 and PA66 composite interlayers

“…3 They also allow to tailor the mechanical behavior of structures through several properties of the constituent layers. 4 Particle reinforced-aluminum matrix composites (PR-AMCs) are well known to have high specific strength and stiffness, 5 improved elevated temperature properties 6 and wear resistance. 7 2xxx series Al alloys, the agehardenable Al-Cu-Mg alloys, are widely chosen as the matrix material because of their excellent fracture toughness and good creep resistance.…”