Microstructural Stability of Friction Stirred AA 2218 Alloy on Tensile Properties at Elevated Temperature

Abstract

The microstructural features of Al-Cu 2218 alloy after FSP were composed mainly of equiaxed 4 mm grains as well as a much more random orientation in SZ comparing to the extruded base metal. In this investigation, tensile properties of FSP specimens displayed an advanced performance than base metal. Furthermore, it should be noted that the FSP specimens possessed great elongation which even more than 100% at 400 C. As the test temperature over 450 C, the deterioration of the elongation could be responsible to second phase particles coarsening during tensile deformation process as well as abnormal grain growth. Ductility was commonly degenerated in both base metal and FSP specimens at 500 C, whole grains within FSP sample grew into large ones that conducted the seriously descent of ductility. It is rational to deduce that the tensile strain promoted the coarsening of particles that would resulted from Ostwald ripening phenomenon. The declination of elongation could be ascribed mainly to the microstructural stability problem at elevated temperature.

Microstructural Variation and Tensile Properties of a Cast 5083 Aluminum Plate via Friction Stir Processing

“…As it has been developed based on basic concept of FSW, this process is often utilized to refine the grain size or to homogenize the heterogeneous intermetallic solidification precipitates. Many previous reports 5,6,14) characterizing the microstructural feature pertaining to dynamic recrystallization have been completed. These studies might lead to a better understanding of friction stir processed alloy 5083, however, FSP and FSW have not been examined on material with such coarse equaxed casting microstructure, and might possess different tensile deformation behavior from other friction stir processed wrought alloys.…”

“…Particularly, when FSW utilized in tailor weld blanks, a post-weld deformation such as pressing and bending works is inevitable. Friction stir processing (FSP), [12][13][14] which is essentially similar to FSW, can be applied to surface modification or a specific local areas of components where better mechanical properties are required. As it has been developed based on basic concept of FSW, this process is often utilized to refine the grain size or to homogenize the heterogeneous intermetallic solidification precipitates.…”

Characteristics and Effects of Particle Morphology and Tensile Ductility Resulting from FSP of Al–Si–Cu–Ni Casting and Forging Piston

“…Based on our previous report, 24) a friction stir processed Al4Cu2Ni aluminum alloy (2218) possessed very similar matrix structure as the material used in this investigation, during tensile deformation numerous tangled dislocations occur initially, and subsequently the subgrains will form preferentially near the broken Ni containing particles or submicron particles. However, elimination of the tangled dislocation and the separation of the broken particles could be recognized, resulting in a very fine subgrain structure with submicron particles (0.10.2 µm) distributed intergranulary pertaining to the promotion of dissolution.…”

Effect of Revolutionary Pitch on the Microhardness Drop and Tensile Properties of Friction Stir Processed 1050 Aluminum Alloy

“…Many precipitation strengthened aluminum alloys demonstrate an aging effect which significantly affects the mechanical properties of FSPed specimens, due to the dissolution [1][2][3][4][5] or coarsening 6) of particles from the imported strain energy or friction heat of FSP.…”