In as-welded state,each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases.After the...In as-welded state,each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases.After the post-weld heat treatment,both the amount and the size of the eutectic structure orθphases decreased.Correspondingly,both the Cu content inα-Al matrix and the microhardness increased to a similar level in each region of the joint,and the tensile strength of the entire joint was greatly improved.Post-weld heat treatment played the role of solid solution strengthening and aging strengthening.After the post-weld heat treatment,the weld performance became similar to other regions,but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect.The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties,and the specimens randomly crack in the weld zone.展开更多
Tungsten inert gas （TIG） welded joints for 2219-T87 aluminum alloy are often used in the fuel tanks of large launch vehicles. Because of the massive loads these vehicles carry, dealing with weld reinforcement on TIG...Tungsten inert gas （TIG） welded joints for 2219-T87 aluminum alloy are often used in the fuel tanks of large launch vehicles. Because of the massive loads these vehicles carry, dealing with weld reinforcement on TIG joints represents an important issue in their manufacturing and strength evaluation. Experimental and numerical simulation methods were used to investigate the effects of weld toe shape and weld toe position on the tensile behavior and mechanical properties of these joints. The simulation results indicated that the relative difference in elongation could be as large as 96.9% caused by the difference in weld toe shape. The joints with weld toes located in the weld metal or in the partially melted zone （PMZ） exhibited larger elongation than joints with weld toes located at the juncture of the weld metal and the PMZ.展开更多
基金supported by the Joint Funds of the National Natural Science Foundation of China (Grant No. U1637601)
文摘In as-welded state,each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases.After the post-weld heat treatment,both the amount and the size of the eutectic structure orθphases decreased.Correspondingly,both the Cu content inα-Al matrix and the microhardness increased to a similar level in each region of the joint,and the tensile strength of the entire joint was greatly improved.Post-weld heat treatment played the role of solid solution strengthening and aging strengthening.After the post-weld heat treatment,the weld performance became similar to other regions,but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect.The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties,and the specimens randomly crack in the weld zone.
文摘Tungsten inert gas （TIG） welded joints for 2219-T87 aluminum alloy are often used in the fuel tanks of large launch vehicles. Because of the massive loads these vehicles carry, dealing with weld reinforcement on TIG joints represents an important issue in their manufacturing and strength evaluation. Experimental and numerical simulation methods were used to investigate the effects of weld toe shape and weld toe position on the tensile behavior and mechanical properties of these joints. The simulation results indicated that the relative difference in elongation could be as large as 96.9% caused by the difference in weld toe shape. The joints with weld toes located in the weld metal or in the partially melted zone （PMZ） exhibited larger elongation than joints with weld toes located at the juncture of the weld metal and the PMZ.
