TC4 titanium alloy was friction stir welded using a W-Re pin tool,and the defect-free weld was produced with proper welding parameters.The joint consists of stir zone,heat affected zone and base material.The stir zone...TC4 titanium alloy was friction stir welded using a W-Re pin tool,and the defect-free weld was produced with proper welding parameters.The joint consists of stir zone,heat affected zone and base material.The stir zone is characterized by equiaxed dynamically recrystallized α phases and transformed β phases with fine α+β lamellar microstructure.The microstructure of the heat-affected zone is similar to that of the base material,but there is an increase in the volume fraction of β.Transverse tensile strength of the joint is 92% that of the base material,and the joint is fractured in the stir zone and the fracture surface possesses typical plastic fracture characteristics.The stir zone is the weakest part of the joint,through which the tensile characteristics of the TC4 joint can be explained.展开更多
The microstructure and mechanical properties of the Mg-6Zn-xEr alloys in the as-cast, as-extruded and extruded-T5 states were investigated. It is found that the addition of Er has an obvious effect on improving mechan...The microstructure and mechanical properties of the Mg-6Zn-xEr alloys in the as-cast, as-extruded and extruded-T5 states were investigated. It is found that the addition of Er has an obvious effect on improving mechanical properties of Mg-6Zn based alloys. The results suggest that the Mg-6Zn-0.5Er alloy in the peak aged state shows the best tensile strength. The ultimate tensile strength and the yield tensile strength of the peak-aged Mg-6Zn-0.5Er alloy are about 329 MPa and 183 MPa, respectively, companying with a good elongation of 12%. The addition of 0.5% Er into the Mg-6Zn based alloys has a great effect on improving ageing hardening response. The highest tensile strength of the peak-aged Mg-6Zn-0.5Er alloy is mainly due to the refinement of microstructure and the precipitation of β1 phase.展开更多
基金Project(2010CB731704) supported by the National Basic Research Program of ChinaProject supported by the Program of Excellent Team in Harbin Institute of Technology, China
文摘TC4 titanium alloy was friction stir welded using a W-Re pin tool,and the defect-free weld was produced with proper welding parameters.The joint consists of stir zone,heat affected zone and base material.The stir zone is characterized by equiaxed dynamically recrystallized α phases and transformed β phases with fine α+β lamellar microstructure.The microstructure of the heat-affected zone is similar to that of the base material,but there is an increase in the volume fraction of β.Transverse tensile strength of the joint is 92% that of the base material,and the joint is fractured in the stir zone and the fracture surface possesses typical plastic fracture characteristics.The stir zone is the weakest part of the joint,through which the tensile characteristics of the TC4 joint can be explained.
基金Project(51071004)supported by the National Natural Science Foundation of ChinaProject(2011BAE22B01-3)supported by the National Key Technology R&D Program during the 12th Five-Year Period,China
文摘The microstructure and mechanical properties of the Mg-6Zn-xEr alloys in the as-cast, as-extruded and extruded-T5 states were investigated. It is found that the addition of Er has an obvious effect on improving mechanical properties of Mg-6Zn based alloys. The results suggest that the Mg-6Zn-0.5Er alloy in the peak aged state shows the best tensile strength. The ultimate tensile strength and the yield tensile strength of the peak-aged Mg-6Zn-0.5Er alloy are about 329 MPa and 183 MPa, respectively, companying with a good elongation of 12%. The addition of 0.5% Er into the Mg-6Zn based alloys has a great effect on improving ageing hardening response. The highest tensile strength of the peak-aged Mg-6Zn-0.5Er alloy is mainly due to the refinement of microstructure and the precipitation of β1 phase.
