This study compared the microstructure and mechanical characteristics of AA6061-T6 joints produced using friction stir welding(FSW),friction stir vibration welding(FSVW),and tungsten inert gas welding(TIG).FSVW is a m...This study compared the microstructure and mechanical characteristics of AA6061-T6 joints produced using friction stir welding(FSW),friction stir vibration welding(FSVW),and tungsten inert gas welding(TIG).FSVW is a modified version of FSW wherein the joining specimens are vibrated normal to the welding line during FSW.The results indicated that the weld region grains for FSVW and FSW were equiaxed and were smaller than the grains for TIG.In addition,the weld region grains for FSVW were finer compared with those for FSW.Results also showed that the strength,hardness,and toughness values of the joints produced by FSVW were higher than those of the other joints produced by FSW and TIG.The vibration during FSW enhanced dynamic recrystallization,which led to the development of finer grains.The weld efficiency of FSVW was approximately 81%,whereas those of FSW and TIG were approximately 74%and 67%,respectively.展开更多
An innovative grade of ferritic stainless steel,ultra-pure 18Cr–2Mo thick plate,was designed and produced for special industrial application.In order to maintain its mechanical properties after joining,three advanced...An innovative grade of ferritic stainless steel,ultra-pure 18Cr–2Mo thick plate,was designed and produced for special industrial application.In order to maintain its mechanical properties after joining,three advanced joining methods,hybrid laser arc welding,activated flux tungsten inert gas welding and friction stir welding,were selected and conducted to connect the thick plates.The feasibility of three joining methods,the microstructure and mechanical properties were compared,and the results have demonstrated that the sound joint was successfully produced using the selected parameters through friction stir welding.The obtained hardness and impact toughness of the weld zone were satisfying.In terms of activated flux tungsten inert gas welding,the crack will be created due to microstructural brittleness.And as for hybrid laser arc welding,the weld zone is narrow,and the addition of wire during welding for the top weld metal area leads to higher formation ratio of low-angle grain boundaries,which is beneficial to performance of the joint.However,there is still a weak area in the fusion line of the welded joint.The result has illustrated that the welding of innovative ultra-pure ferritic stainless steel thick plate by friction stir welding is feasible.展开更多
文摘This study compared the microstructure and mechanical characteristics of AA6061-T6 joints produced using friction stir welding(FSW),friction stir vibration welding(FSVW),and tungsten inert gas welding(TIG).FSVW is a modified version of FSW wherein the joining specimens are vibrated normal to the welding line during FSW.The results indicated that the weld region grains for FSVW and FSW were equiaxed and were smaller than the grains for TIG.In addition,the weld region grains for FSVW were finer compared with those for FSW.Results also showed that the strength,hardness,and toughness values of the joints produced by FSVW were higher than those of the other joints produced by FSW and TIG.The vibration during FSW enhanced dynamic recrystallization,which led to the development of finer grains.The weld efficiency of FSVW was approximately 81%,whereas those of FSW and TIG were approximately 74%and 67%,respectively.
文摘An innovative grade of ferritic stainless steel,ultra-pure 18Cr–2Mo thick plate,was designed and produced for special industrial application.In order to maintain its mechanical properties after joining,three advanced joining methods,hybrid laser arc welding,activated flux tungsten inert gas welding and friction stir welding,were selected and conducted to connect the thick plates.The feasibility of three joining methods,the microstructure and mechanical properties were compared,and the results have demonstrated that the sound joint was successfully produced using the selected parameters through friction stir welding.The obtained hardness and impact toughness of the weld zone were satisfying.In terms of activated flux tungsten inert gas welding,the crack will be created due to microstructural brittleness.And as for hybrid laser arc welding,the weld zone is narrow,and the addition of wire during welding for the top weld metal area leads to higher formation ratio of low-angle grain boundaries,which is beneficial to performance of the joint.However,there is still a weak area in the fusion line of the welded joint.The result has illustrated that the welding of innovative ultra-pure ferritic stainless steel thick plate by friction stir welding is feasible.
