01 Challenges of the Era - Due to their low density, high specific strength, and excellent corrosion resistance, aluminum alloys have become indispensable structural materials in the aerospace, automotive, and energy equipment sectors. Txawm li cas los xij, raws li kev lag luam niaj hnub xav tau rau cov geometries nyuaj thiab siab -kev ua tau zoo, cov khoom sib sib zog nqus tau nce siab, cov txheej txheem casting thiab machining yuav ntsib cov kev txwv tseem ceeb hauv kev tsim cov khoom uas muaj cov kab sib txuas sab hauv, cov qauv lattice, thiab nyias- cov yam ntxwv ntawm phab ntsa. Additive manufacturing technologies-tshwj xeeb yog Laser Powder Bed Fusion (LPBF) thiab Laser Directed Energy Deposition (LDED)- muab txoj hauv kev hloov pauv los kov yeej cov kev tsim khoom no. LPBF thev naus laus zis siv lub siab- lub zog laser beam los xaiv yaj ua ntej- cov hmoov txheej txheej, tsim cov khoom sib xyaw nrog qhov ntom ntom tshaj 99.5% txheej los ntawm txheej; nrog rau cov cua txias ib txwm ncav cuag qhov kev txiav txim ntawm 10⁶ K / s, nws tuaj yeem tsim cov kev daws teeb meem supersaturated thiab ultrafine -grained microstructures nyob deb ntawm qhov sib npaug ntawm cov khoom sib npaug. Lub caij no, LDED thev naus laus zis, siv synchronous hmoov noj thiab laser melting, ua kom pom qhov zoo ntawm kev kho cov khoom puas thiab tsim cov khoom loj - nplai cov khoom siv nrog rau cov khoom sib xyaw ua ke. Txawm li cas los xij, aluminium alloys ntsib ntau yam ntawm lub cev sab hauv-kev sib tw metallurgical thaum lub sij hawm laser additive manufacturing. Nyob rau hauv chav tsev kub, aluminium alloys pom ib tug reflectivity ntau tshaj 90% rau ze -infrared lasers (wavelength: 1070 nm), uas ua rau tsis tshua muaj zog coupling efficiency thiab yuav tsum tau siab - zog- lasers ceev los tsim ib tug ruaj khov melting pas dej ua ke. Aluminium alloy nto tau yooj yim tsim cov oxide zaj duab xis ntom ntom (Al₂O₃) nrog lub melting point ntawm 2072℃-qhov tseem ceeb tshaj qhov 660℃melting point ntawm aluminium matrix; fragments ntawm no oxide zaj duab xis feem ntau tsis yaj kiag li nyob rau hauv lub melting pas dej ua ke, nquag ua hauj lwm raws li pib qhov chaw rau tawg thiab tsis muaj - ntawm - fusion defects. Qhov tseem ceeb tshaj, solubility ntawm hydrogen nyob rau hauv cov kua txhuas (kwv yees . 0.7} cm³/100g) yog siab tshaj nyob rau hauv cov khoom txhuas (kwv yees . 0.04 cm³/100g); Thaum lub sij hawm solidification sai, supersaturated hydrogen atoms tsis tuaj yeem nthuav tawm hauv lub sijhawm thiab hloov pauv ntawm cov khoom -kua interface los ua npuas nuclei, thaum kawg tawm hauv qab metallurgical pores li ntawm ob peb mus rau ntau kaum micrometers inch nyob rau hauv lub solidified microstructure. Lub caij no, qhov sib txawv ntawm qhov kub thiab txias (piv txwv li, ntau tshaj 150℃rau Al7075) thiab qhov tseem ceeb ntawm cov khoom tawg (kwv yees li 6%) ntawm aluminium alloys ua rau lawv muaj kev cuam tshuam rau kev ua kom muaj zog shrinkage porosity thiab kub tawg thaum lub sij hawm pub mis kaw thaum lub sij hawm kawg ntawm lub pas dej ua ke; Cov teeb meem no sawv cev rau cov teeb meem tseem ceeb hauv LPBF kev ua haujlwm siab -lub zog 2xxx thiab 7xxx series aluminium alloys. Cov yam ntxwv tshwj xeeb ntawm kev caij tsheb kauj vab uas muaj nyob rau hauv laser additive manufacturing-nrog rau cov dej kub hauv lub pas dej ua ke siab tshaj 2000℃nrog rau ib puag ncig cov hmoov thiab substrate kub xws li chav tsev kub txog 200 degree, uas ua rau kub gradients siab li 10⁶ K / m- tsim kom muaj cov thermal stress fields nyob rau hauv lub complex; Yog tias tsis muaj kev tswj hwm, cov kev ntxhov siab no tuaj yeem ua rau warping, deformation, los yog interlayer tawg.
02 Composition Design - Nyob rau theem ntawm kev tsim qauv, cov tshuab hlau feem ntau siv rau kev casting thiab forging feem ntau tsis tsim nyog rau kev tsim khoom ntxiv. Noj cov AlSi10Mg alloy ua piv txwv, nws nyob ze -eutectic muaj pes tsawg leeg imparts zoo heev fluidity thaum casting; Txawm li cas los xij, nyob rau hauv cov xwm txheej ceev ceev ntawm LPBF, cov coarse eutectic silicon theem network ua raws li qhov muaj kev ntxhov siab. Tsis tas li ntawd, cov hlau alloy lub zog tensile ntawm 300℃plummets mus rau kwv yees li 10% ntawm nws chav -qhov kub thiab txias - tshwm sim los ntawm kev coarsening sai thiab tawg ntawm eutectic microstructure ntawm qhov kub thiab txias. Yog li ntawd, tsim tshwj xeeb aluminium alloy muaj pes tsawg leeg systems raws li tus yam ntxwv ntawm additive manufacturing tau dhau los ua ib tug tseem ceeb kev tshawb fawb tsom nyob rau hauv lub teb.
Kev tshawb fawb los ntawm Chongqing Institute of Green thiab Intelligent Technology, Suav Academy ntawm Kev Tshawb Fawb, qhia tias ntxiv cov lej ntawm Sc (0.2–0.4 wt%) thiab Zr (0.1–0.3 wt%) rau Al-Mg alloys ua rau * nyob rau hauv qhov chaw * tsim ntawm nanoscale thawj Al₃ (Sc, Zr) cov txheej txheem sai sai Powder txaj Fusion (LPBF). Cov theem no muaj qhov tsis sib xws ntawm lattice tsis sib haum (kwv yees li 1.3%) nrog rau -Al matrix thiab ua haujlwm zoo heev heterogeneous nucleation sites, refining grain loj los ntawm kaum tawm micrometers mus rau sub-micrometer nplai. Txoj kev tshawb no qhia tau hais tias lub as{11}}ua Al-Mg-Mn-Sc-Zr alloy qhia txog tus yam ntxwv bimodal grain qauv: ib cheeb tsam ntawm nplua equiaxed nplej (qhov nruab nrab loj ~ 1.04 μm) nyob rau hauv lub melt pool edges, thiab ib cheeb tsam loj hlob μ 1. kev taw qhia nyob rau hauv lub melt pool center. Qhov no heterogeneous grain qauv tshwm sim los ntawm spatial variations nyob rau hauv kub gradients thiab nucleation densities nyob rau hauv lub melt pas dej ua ke; cov npoo muaj qhov kub thiab txias gradients thiab ua kom muaj txiaj ntsig ntawm thawj Al₃ (Sc, Zr) theem, uas txhawb cov nucleation heterogeneous, whereas qhov chaw yog tus cwj pwm los ntawm kev taw qhia qhov kub thiab txias gradient uas nyiam epitaxial siv lead ua kev loj hlob raws li cov kev taw qhia ntawm qhov siab tshaj plaws kub dissipation. Qhov tseem ceeb, thaum Sc yog kim (kwv yees $ 3,000 / kg), Zr kuj pheej yig (kwv yees $ 30 / kg); kev sib xyaw ua ke ntawm cov ntsiab lus no ua rau Al₃Sc-core / Al₃Zr- plhaub qauv uas tsis tsuas yog txhim kho cov thermal stability ntawm cov theem ntxiv, tab sis kuj txo cov nqi hlau zoo. Lub caij no, ib pab neeg los ntawm Shanghai Jiao Tong University tau tshaj tawm cov tswv yim tsim kho tshiab raws li qhov deformable -transformable eutectic nanoscaffold. Lawv xaiv qhov ze ntawm -eutectic Al-Er system (12.7 wt% Er) raws li cov qauv alloy, siv qhov tsim ntawm L1₂-structured Al₃Er theem- uas nthuav tawm ib lub lattice mismatch ntawm tsuas yog 3.96% ab thiab cov tshuab siab nrog {{3.97} ab al. twinning muaj peev xwm. Thaum lub sij hawm LPBF luam ntawv txheej txheem, Al₃Er precipitates nrog ib feem ntawm kwv yees li 10.3% nyob rau hauv daim ntawv ntawm ib tug nruam 3D nano-skeleton; Cov pob txha no tsis tsuas yog tiv taus cov kev ntxhov siab siab tshaj 1300 MPa tab sis kuj pab txhawb cov yas yas thaum lub sij hawm deformation los ntawm kev tsim ntawm deformation ntxaib thiab 9R ntev - lub sij hawm stacking txiav txim cov qauv, yog li fundamentally overturning cov pa pom tias eutectic skeletons inherently brittle. Raws li - luam tawm Al-Er-Mg alloy (RAE700) nthuav tawm lub zog tawm ntawm 632 MPa, uas nce mus rau 707 MPa tom qab kev laus ncaj qha thaum tuav qhov elongation ntawm 7–10%, ua rau muaj kev ua tau zoo ntawm txhuas profile uas tshaj 5} tag nrho cov ntaub ntawv tshaj tawm 3} Tsis tas li ntawd, ib pab neeg tshawb fawb ntawm Nagoya University tau tsim ib qho Al-Fe-Mn-Ti alloy series raws li "tseem ceeb faib tswj" lub tswv yim; los ntawm kev ntxiv Cu thiab Mn kom ruaj khov rau theem Al₆Fe thiab hloov pauv mus rau theem kev txhawb zog muaj txiaj ntsig-thaum ib txhij qhia Ti uas muab faib rau hauv cov theem khoom ua kom zoo dua cov nplej rau kwv yees li 2.3 μm- cov hlau ua tiav ib chav - qhov kub thiab txias ntawm 390elong. 14-17%, nrog cov khoom seem zoo tsis hloov tom qab 100 teev ntawm thermal raug ntawm 300 degree.
