The paper gives an analysis on technical characteristics of repair techniques for friction stir welding defects. To overcome the defects,a new repair technique, inertia friction pull plug welding( IFPPW), was research...The paper gives an analysis on technical characteristics of repair techniques for friction stir welding defects. To overcome the defects,a new repair technique, inertia friction pull plug welding( IFPPW), was researched and its equipment was developed as well. Elementary datum was achieved by investigating the influences of technological parameters on mechanical properties and by analyzing the structural characteristics of repair joint with IFPPW. The study shows that the stability and reliability of welding process of IFPPW can be guaranteed through the constant energy from the flywheel.Integrated with the advantages of friction pull plug welding,the IFPPW,free from back anvil,is considered as a promising technique in repair of termination keyhole of bobbin tool friction stir welding and point-like defects in aluminum alloy welding.展开更多
Magnesium (Mg) alloys have broad application prospects in the fields of aerospace,national defense,and military industries,owing to their advantages of high specific strength and stiffness,good damping properties,and ...Magnesium (Mg) alloys have broad application prospects in the fields of aerospace,national defense,and military industries,owing to their advantages of high specific strength and stiffness,good damping properties,and excellent castabilities. However,defects such as oxidation inclusions,shrinkage cavities and porosities,and hot cracks are readily generated in Mg alloy components,which seriously reduce the performance stability of the products. Related repair welding technologies for Mg alloys can greatly reduce the rejection rate and production cost,and exhibit significant value in scientific research and engineering application. In this review,the weldability of Mg alloys is introduced firstly according to their physical and chemical properties. Then,various repair welding technologies and pre-weld treatments applicable to Mg alloys are systematically summarized,and the effects of welding parameters as well as heat treatments on the microstructure and performance of the repaired joints are clarified. Finally,the existing problems and development trends of repair welding technologies for Mg alloys are summarized based on the actual engineering application requirements.展开更多
文摘The paper gives an analysis on technical characteristics of repair techniques for friction stir welding defects. To overcome the defects,a new repair technique, inertia friction pull plug welding( IFPPW), was researched and its equipment was developed as well. Elementary datum was achieved by investigating the influences of technological parameters on mechanical properties and by analyzing the structural characteristics of repair joint with IFPPW. The study shows that the stability and reliability of welding process of IFPPW can be guaranteed through the constant energy from the flywheel.Integrated with the advantages of friction pull plug welding,the IFPPW,free from back anvil,is considered as a promising technique in repair of termination keyhole of bobbin tool friction stir welding and point-like defects in aluminum alloy welding.
基金the National Natural Science Foundation of China(Nos. U2037601,51821001,51775334)the Research Program of Joint Research Center of Advanced Spaceflight Technologies of China(No. USCAST2020-31)。
文摘Magnesium (Mg) alloys have broad application prospects in the fields of aerospace,national defense,and military industries,owing to their advantages of high specific strength and stiffness,good damping properties,and excellent castabilities. However,defects such as oxidation inclusions,shrinkage cavities and porosities,and hot cracks are readily generated in Mg alloy components,which seriously reduce the performance stability of the products. Related repair welding technologies for Mg alloys can greatly reduce the rejection rate and production cost,and exhibit significant value in scientific research and engineering application. In this review,the weldability of Mg alloys is introduced firstly according to their physical and chemical properties. Then,various repair welding technologies and pre-weld treatments applicable to Mg alloys are systematically summarized,and the effects of welding parameters as well as heat treatments on the microstructure and performance of the repaired joints are clarified. Finally,the existing problems and development trends of repair welding technologies for Mg alloys are summarized based on the actual engineering application requirements.
