Al Li Cu合金TIG焊后接头软化较为严重,强度仅为母材的55%,为了解决这一问题,研究了焊后固溶+时效热处理对接头组织及力学性能的影响。结果表明,焊后热处理可提高接头的强度,焊态接头经520℃固溶1h+150℃时效10h后强度系数高于0.64。但...Al Li Cu合金TIG焊后接头软化较为严重,强度仅为母材的55%,为了解决这一问题,研究了焊后固溶+时效热处理对接头组织及力学性能的影响。结果表明,焊后热处理可提高接头的强度,焊态接头经520℃固溶1h+150℃时效10h后强度系数高于0.64。但在接头强化的同时,母材却受到了一定程度的弱化,试件经520℃固溶1h+176℃时效10h后,母材处的强度弱化到初始强度的31%,随着时效温度的提高和时效时间的延长,试件母材部位的弱化程度随之增大。展开更多
The effect of the addition of minor amounts of La on the microstructure and mechanicalproperties of an Al-Li-Cu-Mg-Zr alloy was studied.The results showed that in Al-Li alloyssome impurities,such as Fe,Si and Na segre...The effect of the addition of minor amounts of La on the microstructure and mechanicalproperties of an Al-Li-Cu-Mg-Zr alloy was studied.The results showed that in Al-Li alloyssome impurities,such as Fe,Si and Na segregated on the grain boundaries,and the addition ofminor amounts of La decreased the segregation of these impurities.In addition,La could giverise to grain refinement,and retard the growth of precipitates.The tensile properties andtoughness of the Al-Li alloy containing minor amounts of La were improved compared with theLa-free Al-Li alloy.展开更多
A dramatic improvement of strength and ductility of cast Al-2.5Li-1.5Cu-1Zn-0.5Mg-0.15 Zr alloy was obtained by the collaboration of Sc-alloying and optimized ageing scheme.Joint and independent influence of Sc-alloyi...A dramatic improvement of strength and ductility of cast Al-2.5Li-1.5Cu-1Zn-0.5Mg-0.15 Zr alloy was obtained by the collaboration of Sc-alloying and optimized ageing scheme.Joint and independent influence of Sc-alloying and different ageing temperatures were investigated.The results revealed that a substantial increase was realized in the hardness of Sc-containing alloy,and the ageing response time was only influenced by ageing temperature.Coarse and heterogeneousδ'(Al_(3)Li),wideδ'-precipitation free zones(δ'-PFZs),and a large amount of T_(1)(Al_(2)CuLi)precipitates were observed in Sc-containing alloy aged at 175℃,which resulted in superior yield strength and poor elongation.The Sc-containing alloy obtained an excellent combination of ductility(elongation=8.2%)and tensile strength(ultimate strength=565 MPa)suffered to 150℃ ageing for 64 h.The increase in the elongation was mainly due to the combined effect of grain refining,much finerδ',and extremely narrowδ'-PFZs(<10 nm),while the higher strength was mainly attributed to the formation of Al_(3)(Sc,Zr,Li)composite particles and a large amount of S'(Al_(2)CuMg)phase.However,the enhancement of the different ageing temperature(150℃ and 175℃)on the mechanical properties of the alloys without Sc addition was not obvious.展开更多
文摘Al Li Cu合金TIG焊后接头软化较为严重,强度仅为母材的55%,为了解决这一问题,研究了焊后固溶+时效热处理对接头组织及力学性能的影响。结果表明,焊后热处理可提高接头的强度,焊态接头经520℃固溶1h+150℃时效10h后强度系数高于0.64。但在接头强化的同时,母材却受到了一定程度的弱化,试件经520℃固溶1h+176℃时效10h后,母材处的强度弱化到初始强度的31%,随着时效温度的提高和时效时间的延长,试件母材部位的弱化程度随之增大。
文摘The effect of the addition of minor amounts of La on the microstructure and mechanicalproperties of an Al-Li-Cu-Mg-Zr alloy was studied.The results showed that in Al-Li alloyssome impurities,such as Fe,Si and Na segregated on the grain boundaries,and the addition ofminor amounts of La decreased the segregation of these impurities.In addition,La could giverise to grain refinement,and retard the growth of precipitates.The tensile properties andtoughness of the Al-Li alloy containing minor amounts of La were improved compared with theLa-free Al-Li alloy.
基金supported by the National Natural Science Foundation of China(Nos.51871148 and 51821001)the United Fund of National Department of Education and Equipment Development(No.6141A02033245)the National Key R&D Program of China(Grant No.2016YFB0301003)。
文摘A dramatic improvement of strength and ductility of cast Al-2.5Li-1.5Cu-1Zn-0.5Mg-0.15 Zr alloy was obtained by the collaboration of Sc-alloying and optimized ageing scheme.Joint and independent influence of Sc-alloying and different ageing temperatures were investigated.The results revealed that a substantial increase was realized in the hardness of Sc-containing alloy,and the ageing response time was only influenced by ageing temperature.Coarse and heterogeneousδ'(Al_(3)Li),wideδ'-precipitation free zones(δ'-PFZs),and a large amount of T_(1)(Al_(2)CuLi)precipitates were observed in Sc-containing alloy aged at 175℃,which resulted in superior yield strength and poor elongation.The Sc-containing alloy obtained an excellent combination of ductility(elongation=8.2%)and tensile strength(ultimate strength=565 MPa)suffered to 150℃ ageing for 64 h.The increase in the elongation was mainly due to the combined effect of grain refining,much finerδ',and extremely narrowδ'-PFZs(<10 nm),while the higher strength was mainly attributed to the formation of Al_(3)(Sc,Zr,Li)composite particles and a large amount of S'(Al_(2)CuMg)phase.However,the enhancement of the different ageing temperature(150℃ and 175℃)on the mechanical properties of the alloys without Sc addition was not obvious.
