De-twinning and Texture Change in an Extruded AM30 Magnesium Alloy during Compression along Normal Direction
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2015年第3期
论文作者：D.Sarker J.Friedman D.L.Chen
文章页码：264 - 268
摘 要：Twinning and de-twinning are the salient deformation mechanisms in hexagonal close-packed（hcp）metals. The aim of this study was to examine and quantify the de-twinning process involving a reversible motion of twin boundaries in an extruded AM30 magnesium alloy after re-compression along the normal direction（ND） of pre-compressed samples along the extrusion direction（ED）. {1012} extension twins were first introduced at a compressive strain of 3.7% along the ED. The subsequent compressive deformation along the ND induced a gradual shrinkage of twins with increasing cumulative true strain,and the complete de-twinning occurred at a strain of 7.7%. The twin width decreased linearly with increasing true strain. Texture measurements verified the rotation of c-axes of hcp unit cells towards the anti-compression direction due to {1012} extension twinning after compression along the ED, and a gradual return of c-axes to the initial orientation due to twin shrinking or de-twinning during the following compression along the ND. The {1012} twinning corresponded to the formation of new texture components C{1210}<0001> and D{0110}<0001> and a decrease in the initial texture components A{0001}<2110> and B{0001}<1010>, while the twin shrinking or de-twinning was characterized by a gradual vanishing of components C{1210}<0001> and D{0110}<0001> and an increase in the components A{0001}<2110> and B{0001}<1010>.
D.Sarker，J.Friedman，D.L.Chen
Department of Mechanical and Industrial Engineering, Ryerson University
摘 要：Twinning and de-twinning are the salient deformation mechanisms in hexagonal close-packed（hcp）metals. The aim of this study was to examine and quantify the de-twinning process involving a reversible motion of twin boundaries in an extruded AM30 magnesium alloy after re-compression along the normal direction（ND） of pre-compressed samples along the extrusion direction（ED）. {1012} extension twins were first introduced at a compressive strain of 3.7% along the ED. The subsequent compressive deformation along the ND induced a gradual shrinkage of twins with increasing cumulative true strain,and the complete de-twinning occurred at a strain of 7.7%. The twin width decreased linearly with increasing true strain. Texture measurements verified the rotation of c-axes of hcp unit cells towards the anti-compression direction due to {1012} extension twinning after compression along the ED, and a gradual return of c-axes to the initial orientation due to twin shrinking or de-twinning during the following compression along the ND. The {1012} twinning corresponded to the formation of new texture components C{1210}<0001> and D{0110}<0001> and a decrease in the initial texture components A{0001}<2110> and B{0001}<1010>, while the twin shrinking or de-twinning was characterized by a gradual vanishing of components C{1210}<0001> and D{0110}<0001> and an increase in the components A{0001}<2110> and B{0001}<1010>.
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