Friction Stir Welding of Ceramic Particle Reinforced Aluminium Based Metal Matrix Composites

Abstract

Abstract. The mechanical and microstructural properties of 6061 + 20% Al 2 O 3p and 7005 + 10% Al 2 O 3p aluminium based metal matrix composites joined by friction stir welding were analyzed in the present study. The two materials were welded into the form of sheets of 7 mm thickness after T6 treatment and were tested in tension at room temperature. The microstructure of the joints was observed by optical microscopy and the fracture surfaces were analyzed by employing a scanning electron microscope equipped with field emission gun in order to study the micromechanisms involved during the deformation.

A Semi-Analytical Model for the Heat Generation during Hybrid Metal Extrusion and Bonding (HYB)

“…As a consequence, the welds produced will largely retain their microstructural integrity without forming a fusion zone and a wide heat-affected zone (HAZ) with degraded properties, which is the main problem with traditional fusion welding [3,4]. In addition, they allow the joining of materials that are known to be prone to hot cracking and pore formation, with no hazardous fume formation, radiation from an open arc, or oxidation losses of alloying elements [5][6][7][8][9]. Therefore, the benefits of solid-state joining are obvious and well documented.…”

Friction stir welding on aluminum 6092/sic/25p/t6 metal matrix composite: Its microstructure evolution and mechanical properties

“…Typical onion flow was observed on these kinds of welds (Fig. 3), which was caused by the material flow during the joining process [3]. It was also observed during the welding, there was minimal occurrence of splatter at the side of the welding line.…”

“…Results from table 1 shows that there is a high distortion in the space lattice between the welding regions (d spacing) which induces some stresses within the material matrix. Such stresses could cause failure within the zone during tensile test [6]. Further study SiC Pariculate SiC Pariculate…”

Mechanical and Microstructural Behaviour of 6061/AL

“…Even if the grain size in the nugget zone is smaller respect to the rest of the weld, the increase of hardness near the weld line is due to the strong decreasing particles dimensions which lead to an increase in mechanical properties governing the mechanical behaviour of the material; Fig.6 shows the difference in grain size of the nugget zone respect to the thermo-mechanical affected zone, in the nugget zone the mean grain diameter measured 4 m μ with a standard deviation of 1while in the thermo-mechanical affected zone the mean grain diameter The demonstration of the better microstructure of the nugget respect to the parent material was demonstrated by the room temperature tensile tests performed on samples obtained by EDM along the welds. In a previous paper [8] the author has published the room temperature tensile properties of such joints respect to the parent material; in Table I are reported these data with the addition of the tensile response of the nugget material. The centre of the joints reveals higher yield strength and UTS accompanied with an increase in ductility respect to the tests performed perpendicularly to the welding direction and respect to the parent material (Fig.7).…”

“…In particular, for the aluminium based metal matrix composites, the welding is a critical problem because of the presence of the reinforcing particles which debond and segregate in a very severe way during fusion welding processes. As a consequence, the control of microstructure of such materials is more crucial compared with the unreinforced alloys [8,9], the presence of reinforcing particles create large problems related to the formation of brittle dendritic structures, the creation of large voids and the formation of aluminium carbides in the case of SiC reinforcements. The strong improvement in welding technology of MMCs due to the introduction of FSW and the comparison with the properties of the traditional fusion techniques welds were largely described by Mishra et al [10].…”