The effects of Sr and Y on microstructure,tensile property and free bulge formability of AZ31 alloy sheet produced by twin-roll casting and sequential hot rolling were investigated to improve the mechanical properties...The effects of Sr and Y on microstructure,tensile property and free bulge formability of AZ31 alloy sheet produced by twin-roll casting and sequential hot rolling were investigated to improve the mechanical properties and formability of the AZ31 alloy.Sr and Y addition can form Al4 Sr,Al2 Y and Al3 Y phases which can impede dislocation movement and promote dynamic recrystallization during the rolling deformation and decrease the lattice resistance to dislocation motion by decreasing Al solubility in the alloy,resulting in finer grains,lower dislocation density and no twinning generating in the twin-roll casting and sequential hot rolling(TRC-HR)AZ31-1.3 Sr-1.0 Y alloy.The maximum stress and elongation of the alloy increase significantly after adding Sr and Y.The average cavity and grain sizes of the TRC-HR AZ31-1.3 Sr-1.0 Y alloy are smaller,resulting in higher elongation in the alloy.The addition of Y and Sr can effectively improve the free bulge formability and the thickness uniform of the alloy.The Al4 Sr,Al2 Y and A13 Y phases can inhibit the grain growth by obstructing dislocation motion or grain boundary slip,resulting in smaller grain size of AZ31-1.3 Sr-1.0 Y alloy bulge parts.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51705038 and51875053)the Natural Science Foundation of Jiangsu Province of China(No.BK20150268)。
文摘The effects of Sr and Y on microstructure,tensile property and free bulge formability of AZ31 alloy sheet produced by twin-roll casting and sequential hot rolling were investigated to improve the mechanical properties and formability of the AZ31 alloy.Sr and Y addition can form Al4 Sr,Al2 Y and Al3 Y phases which can impede dislocation movement and promote dynamic recrystallization during the rolling deformation and decrease the lattice resistance to dislocation motion by decreasing Al solubility in the alloy,resulting in finer grains,lower dislocation density and no twinning generating in the twin-roll casting and sequential hot rolling(TRC-HR)AZ31-1.3 Sr-1.0 Y alloy.The maximum stress and elongation of the alloy increase significantly after adding Sr and Y.The average cavity and grain sizes of the TRC-HR AZ31-1.3 Sr-1.0 Y alloy are smaller,resulting in higher elongation in the alloy.The addition of Y and Sr can effectively improve the free bulge formability and the thickness uniform of the alloy.The Al4 Sr,Al2 Y and A13 Y phases can inhibit the grain growth by obstructing dislocation motion or grain boundary slip,resulting in smaller grain size of AZ31-1.3 Sr-1.0 Y alloy bulge parts.
