A new designed surface strengthening method, surface spinning strengthening （3S）, was applied to achieve gradient microstructure in the surface layer of a Cu-11 at.%A1 alloy. According to the level of grain refineme...A new designed surface strengthening method, surface spinning strengthening （3S）, was applied to achieve gradient microstructure in the surface layer of a Cu-11 at.%A1 alloy. According to the level of grain refinement, the gradient microstructure can be divided into four zones, including nanoscale grain zone, ultra-fine grain zone, fine grain zone and coarse grain zone from the surface to the matrix. Meanwhile, a plenty of grain boundaries and twin boundaries were introduced to inhibit the dislocation motion in the surface layer during the plastic deformation process. Consequently, the hardened layer with a microhardness gradient and high residual compressive stress was produced on the samples, and the yield strength of the Cu-11 at.%A1 alloy was effectively improved after 3S processing due to the strengthening effect caused by the gradient microstructurc.展开更多
The bainitic transformation in a Cu-Zn-Al-Mn alloy has been examined with TEM.The re- sults show that the stacking faults and also the bainitic midrib are found at the beginning of bainite formation in the alloy.The s...The bainitic transformation in a Cu-Zn-Al-Mn alloy has been examined with TEM.The re- sults show that the stacking faults and also the bainitic midrib are found at the beginning of bainite formation in the alloy.The stacking fault planes can pass continuously through the midrib in bainite.The growth ledges occur at the broad faces and rims of bainite.The broad and narrow faces of th ledges are parallel to the fault plane and habit plane respectively.Both their Miller indices are {110}_(B2).The moving direction of ledges is parallel to the fault plane. It may be deduced that the bainite in alloy are initially formed by shear and the process of growth are go verned by propagation o f fault planes.展开更多
基金financially supported by the National Natural Science Foundation of China(NSFC) under Grant Nos.51331007 and 51501198
文摘A new designed surface strengthening method, surface spinning strengthening （3S）, was applied to achieve gradient microstructure in the surface layer of a Cu-11 at.%A1 alloy. According to the level of grain refinement, the gradient microstructure can be divided into four zones, including nanoscale grain zone, ultra-fine grain zone, fine grain zone and coarse grain zone from the surface to the matrix. Meanwhile, a plenty of grain boundaries and twin boundaries were introduced to inhibit the dislocation motion in the surface layer during the plastic deformation process. Consequently, the hardened layer with a microhardness gradient and high residual compressive stress was produced on the samples, and the yield strength of the Cu-11 at.%A1 alloy was effectively improved after 3S processing due to the strengthening effect caused by the gradient microstructurc.
文摘The bainitic transformation in a Cu-Zn-Al-Mn alloy has been examined with TEM.The re- sults show that the stacking faults and also the bainitic midrib are found at the beginning of bainite formation in the alloy.The stacking fault planes can pass continuously through the midrib in bainite.The growth ledges occur at the broad faces and rims of bainite.The broad and narrow faces of th ledges are parallel to the fault plane and habit plane respectively.Both their Miller indices are {110}_(B2).The moving direction of ledges is parallel to the fault plane. It may be deduced that the bainite in alloy are initially formed by shear and the process of growth are go verned by propagation o f fault planes.
基金supported by the National Natural Science Foundation of China(50772107)National Key Basic Research Program of China(973)(2007CB210206)National High-Tech Research and Development Program of China(863)(2009AA05Z435)~~
