In this study, the ultrafine grained （UFG） 6061 Al alloys fabricated by cold rolling were friction stir welded （FSW） with different rotation rates under both air cooling and rapid cooling in water. Low-heat-input ...In this study, the ultrafine grained （UFG） 6061 Al alloys fabricated by cold rolling were friction stir welded （FSW） with different rotation rates under both air cooling and rapid cooling in water. Low-heat-input parameters of 400 rpm rotation rate in water （400-Water） could effectively inhibit the coarsening of recrystallized grains, reduce the precipitation rate, and retain more dislocations of the UFG 6061 Al parent metal. 400-Water joint showed high lowest-hardness value, narrow low-hardness zone, and high tensile strength, attributing to the effect of dislocation, grain boundary, solid-solution, and precipitation hardening. This work provides an effective strategy to fabricate large-sized bulk UFG AI alloy by cold rolling with large deformation and low-heat-input FSW.展开更多
基金funded by the National Natural Science Foundation of China(No.51601045)the Guangxi Natural Science Foundation(No.2015GXNSFBA139238)+2 种基金the Guangxi ‘Bagui’ Teams for Innovation and Researchthe National Basic Research Program of China(No.2013CB733000)the Collaborative Innovation Center for Exploration of Hidden Nonferrous Metal Deposits and Development of New Materials in Guangxi
文摘In this study, the ultrafine grained （UFG） 6061 Al alloys fabricated by cold rolling were friction stir welded （FSW） with different rotation rates under both air cooling and rapid cooling in water. Low-heat-input parameters of 400 rpm rotation rate in water （400-Water） could effectively inhibit the coarsening of recrystallized grains, reduce the precipitation rate, and retain more dislocations of the UFG 6061 Al parent metal. 400-Water joint showed high lowest-hardness value, narrow low-hardness zone, and high tensile strength, attributing to the effect of dislocation, grain boundary, solid-solution, and precipitation hardening. This work provides an effective strategy to fabricate large-sized bulk UFG AI alloy by cold rolling with large deformation and low-heat-input FSW.
