The effect of Yb addition on the strength and fracture toughness of Al-Zn-Mg-Cu-Zr aluminum alloy was investigated by measuring tensile properties and fracture toughness.The surface morphology was observed by optical ...The effect of Yb addition on the strength and fracture toughness of Al-Zn-Mg-Cu-Zr aluminum alloy was investigated by measuring tensile properties and fracture toughness.The surface morphology was observed by optical microscopy,scanning electron microscopy and transmission electron microscopy.The results show that Yb addition can produce fine coherent Yb contained dispersoids.Those dispersoids trend to inhibit Al matrix recrystallization and retain the recovery deformed microstructure.Compared with Al-Zn-Mg-Cu-Zr alloy,Yb contained alloy demonstrates mechanical property improvements from 710 MPa to 747 MPa for ultimate strength,from 684 MPa to 725 MPa for yield strength,from 21 MPa.m1/2 to 29 MPa.m1/2 for fracture toughness with T6 treatment.展开更多
Based on the 3 factors and 3 levels orthogonal experiment method,compositional effects of Mg,Si,and Ti addition on the microstructures,tensile properties,and fracture behaviors of the high-pressure die-casting Al-x Mg...Based on the 3 factors and 3 levels orthogonal experiment method,compositional effects of Mg,Si,and Ti addition on the microstructures,tensile properties,and fracture behaviors of the high-pressure die-casting Al-x Mg-y Si-z Ti alloys have been investigated.The analysis of variance shows that both Mg and Si apparently infl uence the tensile properties of the alloys,while Ti does not.The tensile mechanical properties are comprehensively infl uenced by the amount of eutectic phase(α-Al+Mg2Si),the average grain size,and the content of Mg dissolved intoα-Al matrix.The optimized alloy is Al-7.49 Mg-3.08 Si-0.01 Ti(wt%),which exhibits tensile yield strength of 219 MPa,ultimate tensile strength of 401 MPa,and elongation of 10.5%.Furthermore,contour maps,showing the relationship among compositions,microstructure characteristics,and the tensile properties are constructed,which provide guidelines for developing high strength and toughness Al–Mg–Si–Ti alloys for high-pressure die-casting.展开更多
Mechanisms influencing the mechanical properties and fractography of alloy 2090+Ce with different aging conditions were examined as a function of delamination and other factors. It is seen that the alloy aged at 150℃...Mechanisms influencing the mechanical properties and fractography of alloy 2090+Ce with different aging conditions were examined as a function of delamination and other factors. It is seen that the alloy aged at 150℃ has superior fracture resistance to the one aged at 163℃ and the practice of aging at 150℃ for 28 h renders the alloy better strength toughness combination than that of aging at 163℃ for 20 h, due to higher effect of intrinsic toughening of the former. With crack extension, failure mechanism in CT specimens changes from a tougher one to a more brittle one because of increasing strain in the frontal zone of crack tip. Moreover, a model for the improvement of toughness of the alloy, as well as monolithic laminated materials, is developed based on the observation of delamination process.展开更多
基金Project(2005CB623704)supported by the National Basic Research Program of ChinaProject(50721003)supported by the Creative Research Group of National Natural Science Foundation of China
文摘The effect of Yb addition on the strength and fracture toughness of Al-Zn-Mg-Cu-Zr aluminum alloy was investigated by measuring tensile properties and fracture toughness.The surface morphology was observed by optical microscopy,scanning electron microscopy and transmission electron microscopy.The results show that Yb addition can produce fine coherent Yb contained dispersoids.Those dispersoids trend to inhibit Al matrix recrystallization and retain the recovery deformed microstructure.Compared with Al-Zn-Mg-Cu-Zr alloy,Yb contained alloy demonstrates mechanical property improvements from 710 MPa to 747 MPa for ultimate strength,from 684 MPa to 725 MPa for yield strength,from 21 MPa.m1/2 to 29 MPa.m1/2 for fracture toughness with T6 treatment.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0301001)the Science&Technology Program of Zhaoqing(No.2018K006)。
文摘Based on the 3 factors and 3 levels orthogonal experiment method,compositional effects of Mg,Si,and Ti addition on the microstructures,tensile properties,and fracture behaviors of the high-pressure die-casting Al-x Mg-y Si-z Ti alloys have been investigated.The analysis of variance shows that both Mg and Si apparently infl uence the tensile properties of the alloys,while Ti does not.The tensile mechanical properties are comprehensively infl uenced by the amount of eutectic phase(α-Al+Mg2Si),the average grain size,and the content of Mg dissolved intoα-Al matrix.The optimized alloy is Al-7.49 Mg-3.08 Si-0.01 Ti(wt%),which exhibits tensile yield strength of 219 MPa,ultimate tensile strength of 401 MPa,and elongation of 10.5%.Furthermore,contour maps,showing the relationship among compositions,microstructure characteristics,and the tensile properties are constructed,which provide guidelines for developing high strength and toughness Al–Mg–Si–Ti alloys for high-pressure die-casting.
文摘Mechanisms influencing the mechanical properties and fractography of alloy 2090+Ce with different aging conditions were examined as a function of delamination and other factors. It is seen that the alloy aged at 150℃ has superior fracture resistance to the one aged at 163℃ and the practice of aging at 150℃ for 28 h renders the alloy better strength toughness combination than that of aging at 163℃ for 20 h, due to higher effect of intrinsic toughening of the former. With crack extension, failure mechanism in CT specimens changes from a tougher one to a more brittle one because of increasing strain in the frontal zone of crack tip. Moreover, a model for the improvement of toughness of the alloy, as well as monolithic laminated materials, is developed based on the observation of delamination process.
