Effect of initial temper on mechanical properties of friction stir welded Al-2024 alloy

Abstract

The microstructural evolution and resultant mechanical properties during the friction stir welding (FSW) of precipitation strengthened aluminium alloys depend on initial temper as well as FSW process parameters. Al-2024 alloy under two different initial tempers, T3 and T8, was used in the present study. FSW bead-on-plate runs were performed at different values of process parameters (tool rotation rate and tool traverse speed). Microstructure and mechanical properties of the nugget region and heat affected zone (HAZ) were evaluated. Differential scanning calorimetry (DSC) revealed that in the nugget region, presence of Guinier-Preston-Bagaryatskii (GPB) zone results from the partial dissolution of Al 2 CuMg phase. The microstructure and tensile properties were found to be independent of the initial temper of the material in the nugget region. In the HAZ region, tensile properties increased at higher heat index values for T3 condition, and decreased monotonically for T8 condition.

Effect of friction stir processing on the tensile and fatigue behavior of a cast A206 alloy

“…This is similar to the results on AA2024, an Al-Cu-Mg alloy [21,22] where coherent GPB (GuinierPreston-Bagaryatski) zones were observed in the nugget region. GPB zones are coherent fine precipitates of this system equivalent to the GP zones of the Al-Cu system.…”

Effect of welding heat input and post-welding natural aging on hardness of stir zone for friction stir-welded 2024-T3 aluminum alloy thin-sheet

“…Dixit et al found that the increase in HI value significantly affected the microstructural evolution of 2024-T3 aluminium alloy FSW joints. Based on it they proposed a weld parameter range to achieve better mechanical properties of the weld joints [18]. Apart from the weld parameters, the weld conditions such as the plate thickness and ambient temperature also have important effects on the hardness in the FSW joints.…”

“…Several studies have been conducted to evaluate the microstructures [4][5][6][7][8][9], mechanical properties [10][11][12][13][14][15][16][17][18], corrosion performance [19][20][21], and formation mechanisms [22][23][24] of FSW joints for these alloys. As an aged hardening aluminum alloy, an FSW joint had tensile properties that are closely related to the distribution of microhardness, indicating that tensile fracture often occurs at the position with a minimum hardness value along the transversal direction of the FSW joints.…”

The Mechanism of Grain Coarsening in Friction-Stir-Welded AA5083 after Heat Treatment

“…[4] Severe microstructural changes can occur in the welded region. [4,[18][19][20][21][22][23][24][25] Peak temperatures, reportedly as high as 0.6 to 0.8 times the melting temperature, [26][27][28] have been correlated to combinations of welding parameters m (weld feed rates) and x (tool rotation speeds) through a ''heat input parameter'' or a ''heat index,'' x 2 /m [26,29] or x/m, [30] respectively.…”