Comparative study of microstructure and texture of cast and homogenized TX32 magnesium alloy after hot deformation

Abstract

The effect of homogenization on the hot deformation behavior and texture evolution of Mg-3Sn-2Ca (TX32) alloy is investigated. The cast-homogenized alloy samples were hot compressed in the temperature and strain rate ranges of 300-500°C and 0.0003-10 s -1 , respectively, and a processing map has been developed by using the flow stress data. The map revealed two dynamic recrystallization (DRX) domains with a peak efficiency of 44% at 360°C/0.0003 s -1 (Domain 1) and 43% at 485 ○ C/0.1 s -1 (Domain 2). When compared with the map for as-cast condition, it is observed that both the domains moved towards higher temperatures although the shift of Domain 1 is more noticeable. The apparent activation energy values in the two domains and the regime of flow instability are nearly unchanged by homogenization, suggesting that Mg2Ca and CaMgSn particles in the microstructure are thermally stable. Specimens deformed under conditions in Domain 1 have high Schmid factors for {0001} <1120> basal slip and {1100} < 1120> prismatic slip, while in Domain 2 the deformation progressed due to {112 2} <112 3> second-order pyramidal slip.

Influence of constraint condition on rolling behavior of magnesium alloy at low temperatures

“…Magnesium alloys, which have high specific strengths and low densities, are increasingly attracting attention because of their potential for use as materials for lightweight structural components [1][2][3]. However, such alloys exhibit poor formability at low temperatures, owing to the fact that their numbers of activating slip systems are insufficient to satisfy the von Mises yield criterion and because of their specific texture, which develops during the manufacturing process [4,5].…”

Effect of differential speed rolling on the texture evolution of Mg-4Zn-1Gd alloy

“…Two major approaches are possible that can make Mg alloys have weaker and random textures; 1) the addition of alloying elements, such as rare earth (RE) elements and Ca and 2) the application of severe plastic deformation (SPD) processes. First, it has recently been reported that the alloys containing Ca and RE elements such as Y ad Nd can develop more random textures [5][6][7][8][9][10][11][12][13][14][15], especially a splitting of basal poles from the normal direction (ND) towards the transverse direction (TD) with a broadening of angular distribution of basal poles from the ND towards the TD. Second, it has been reported that SPD processes such as equal channel angular processing, high temperature rolling, differential speed rolling (DSR), and etc, can also develop more random textures [16][17][18][19][20][21][22].…”