The new generation of Sc and Zr modified Al alloys has been attracted wide concerns in aerospace industry,owing to the excellent mechanical performances and superior thermal stability than other normal Al alloys.By mi...The new generation of Sc and Zr modified Al alloys has been attracted wide concerns in aerospace industry,owing to the excellent mechanical performances and superior thermal stability than other normal Al alloys.By microalloying with Sc and Zr,the Al3(Sc,Zr)particle forms as the grain refiner during the solidification,which is extremely beneficial for the laser powder bed fusion(LPBF)processed Al alloys.In this study,a new type Al-14.1 Mg-0.47 Si-0.31 Sc-0.17 Zr alloy was additively manufactured by LPBF,and the microstructure,tensile properties and thermal stability were studied in detail.By using a single melt-67°scanning strategy,the LPBF-processed specimen with a relative density of 99.4%and tensile strength of 487.7 MPa was obtained at 160 W-200 mm/s.And this AlMgSiScZr alloy can still exhibit an excellent tensile strength of 393.9 MPa at a moderate temperature of 473 K.After the aging treatment,the tensile properties further increased due to the precipitate hardening of Mg2Si and Al3(Sc,Zr),and the maximum value(580 MPa)was reached at an aging time of 10 h.The average crystal size was almost unchanged after aging treated at 325℃and 24 h,indicating this AlMgSiScZr alloy has an improved thermal stability.The AlMgSiScZr alloy is recommended to substitute some particular titanium alloys in aerospace field afterwards.展开更多
A novel Al-14.1 Mg-0.47 Si-0.31 Sc-0.17 Zr alloy was applied in the printing process of selective laser melting(SLM),and the corresponding microstructural feature,phase identification,tensile properties and corrosion ...A novel Al-14.1 Mg-0.47 Si-0.31 Sc-0.17 Zr alloy was applied in the printing process of selective laser melting(SLM),and the corresponding microstructural feature,phase identification,tensile properties and corrosion behavior of the Al Mg Si Sc Zr alloy were studied in detail.As fabricated at 160 W and 200 mm/s,the Mg content of bulk sample decreased to 11.7 wt%due to the element vaporization at high energy density,and the density of this additively manufactured Al Mg Si Sc Zr alloy was 2.538 g/cm^(3),which is4.2%8.5%lighter than that of other SLM-processed Al alloys.After heat-treated(HT)at 325℃and 6 h,the microstructure was almost unchanged with an alternate distribution of fine equiaxed crystals and coarse columnar crystals.Nano-sized Al3(Sc,Zr)and Mg_(2)Si phases precipitated dispersedly in the Al matrix,and the tensile strength increased from 487.6 MPa to 578.4 MPa for precipitation strengthening and fine grain strengthening.With a fine grain size of 2.53μm,an excellent corrosion resistance was obtained for the as-printed(AP)Al Mg Si Sc Zr alloy.While the corrosion resistance of HT sample decreased slightly for the formation of non-dense oxide layer and pitting corrosion induced by diffuse precipitation distribution.This SLM-printed Al Mg Si Sc Zr alloy with high specific strength,good thermal stability and excellent corrosion resistance has broad prospects for the aerospace and automotive applications.展开更多
文摘The new generation of Sc and Zr modified Al alloys has been attracted wide concerns in aerospace industry,owing to the excellent mechanical performances and superior thermal stability than other normal Al alloys.By microalloying with Sc and Zr,the Al3(Sc,Zr)particle forms as the grain refiner during the solidification,which is extremely beneficial for the laser powder bed fusion(LPBF)processed Al alloys.In this study,a new type Al-14.1 Mg-0.47 Si-0.31 Sc-0.17 Zr alloy was additively manufactured by LPBF,and the microstructure,tensile properties and thermal stability were studied in detail.By using a single melt-67°scanning strategy,the LPBF-processed specimen with a relative density of 99.4%and tensile strength of 487.7 MPa was obtained at 160 W-200 mm/s.And this AlMgSiScZr alloy can still exhibit an excellent tensile strength of 393.9 MPa at a moderate temperature of 473 K.After the aging treatment,the tensile properties further increased due to the precipitate hardening of Mg2Si and Al3(Sc,Zr),and the maximum value(580 MPa)was reached at an aging time of 10 h.The average crystal size was almost unchanged after aging treated at 325℃and 24 h,indicating this AlMgSiScZr alloy has an improved thermal stability.The AlMgSiScZr alloy is recommended to substitute some particular titanium alloys in aerospace field afterwards.
文摘A novel Al-14.1 Mg-0.47 Si-0.31 Sc-0.17 Zr alloy was applied in the printing process of selective laser melting(SLM),and the corresponding microstructural feature,phase identification,tensile properties and corrosion behavior of the Al Mg Si Sc Zr alloy were studied in detail.As fabricated at 160 W and 200 mm/s,the Mg content of bulk sample decreased to 11.7 wt%due to the element vaporization at high energy density,and the density of this additively manufactured Al Mg Si Sc Zr alloy was 2.538 g/cm^(3),which is4.2%8.5%lighter than that of other SLM-processed Al alloys.After heat-treated(HT)at 325℃and 6 h,the microstructure was almost unchanged with an alternate distribution of fine equiaxed crystals and coarse columnar crystals.Nano-sized Al3(Sc,Zr)and Mg_(2)Si phases precipitated dispersedly in the Al matrix,and the tensile strength increased from 487.6 MPa to 578.4 MPa for precipitation strengthening and fine grain strengthening.With a fine grain size of 2.53μm,an excellent corrosion resistance was obtained for the as-printed(AP)Al Mg Si Sc Zr alloy.While the corrosion resistance of HT sample decreased slightly for the formation of non-dense oxide layer and pitting corrosion induced by diffuse precipitation distribution.This SLM-printed Al Mg Si Sc Zr alloy with high specific strength,good thermal stability and excellent corrosion resistance has broad prospects for the aerospace and automotive applications.
