The Compression Behavior In Different Initial Orientations Of Zirconium Alloy

In this paper, the as received material was annealed Zr alloy plate after hot rollingwith bimodal basal texture. Four cylinder specimens for compression were cut from theplate with compressive axes aligned in normal direction-transverse direction (ND-TD)plane and0°,30°,60°and90°to ND respectively. Uniaxial compression was performedat different temperatures and strain rates. Microstructures and textures of specimensbefore and after compression were characterized with EBSD equipped in SEM. Schmidfactors for slip systems and twinning variants were calculated according to the datacollected from EBSD. Effects of initial orientation on mechanical behavior, workhardening and dynamical recrystallization behavior were discussed in detail. Therelationship between mechanical properties and microstructure was study systematically.Main conclusions drew from the paper are as following:The macroscopic flow stress declines with the increase of initial angle betweencompressive axis and ND during compressive deformation. At high temperature, thehigher the initial angle, the weaker effect of the recrystallization is observed. Thefeatures of continuous recrystallization is observed after deformed.In all of the four specimens, the c axis of most grains are turned to directionparallel to compressive axis after60%compression and the specimens all show thebimodal basal texture.It is found that Schmid factors for prismatic slip increase gradually with the initialangle. That is, the greater the initial angle, it is easier for prismatic slip to activate. As aresult, in0°and30°specimens prismatic slip much more difficult to operate comparedwith other specimens with higher angle. Thus higher external stress is required toactivate pyramidal <c+a>to coordinate plastic strain.The amount of primary {10(?)2} tensile twinning goes up with the initial anglebetween compressive axis and ND when the specimens were deformed at roomtemperature and650℃. Twinning plays a crucial role in rotating lattice of grains andchange of the texture in90°specimen.{10(?)1} compressive twinning and a small amountof {10(?)1}-{10(?)2} secondary twinningare also observed in0°and30°specimens afterdeformation at650℃.With respect to {10(?)2} tensile twinning, in the grains with only one type of variantactivatedthe variant with highest SF is most likely to occur. However, Schmid law fail to apply in grains with more than one variant activated.