Archeology-inspired enhancement strategy for aluminum alloys

{"Metal":[0],"casting":[1],"naturally":[2,36,99],"produces":[3],"a":[4,98,106,110,134],"fine-grained":[5,107],"chill":[6,49,66,127],"layer":[7,15,50,67,128],"at":[8],"the":[9,31,48,65,122,126],"mold":[10],"interface,":[11],"although":[12],"this":[13,35],"surface":[14,89,108,147],"is":[16],"commonly":[17],"removed":[18],"during":[19],"machining.":[20],"Inspired":[21],"by":[22,72,85,91],"archeological":[23],"observations":[24],"of":[25,33,125],"ancient":[26],"Cu-Sn":[27],"bronzes,":[28,46],"we":[29],"investigated":[30],"effects":[32],"preserving":[34,64],"formed":[37,100],"metallic":[38],"\\"skin\\"":[39],"in":[40,55,104],"modern":[41],"A356":[42,62],"aluminum":[43,140],"alloys.":[44],"In":[45,61],"retaining":[47],"reduced":[51],"corrosion":[52],"current":[53],"densities":[54],"neutral,":[56],"alkaline,":[57],"and":[58,87,109,116,129],"acidic":[59],"environments.":[60],"alloys,":[63],"increased":[68,88],"ultimate":[69],"tensile":[70],"strength":[71],"up":[73],"to":[74,80],"10%,":[75],"improved":[76],"elongation":[77],"from":[78],"4.1%":[79],"5.8%,":[81],"enhanced":[82],"fatigue":[83],"endurance":[84],"14%,":[86],"hardness":[90],"20%.":[92],"These":[93,119],"improvements":[94],"are":[95],"associated":[96],"with":[97],"hierarchical":[101],"grain":[102],"structure,":[103],"which":[105],"coarser":[111],"interior":[112],"promote":[113],"Hall-Petch":[114],"strengthening":[115],"hetero-deformation-induced":[117],"hardening.":[118],"results":[120],"highlight":[121],"functional":[123],"significance":[124],"suggest":[130],"its":[131],"preservation":[132],"as":[133],"design":[135],"consideration":[136],"for":[137],"improving":[138],"cast":[139],"alloys":[141],"without":[142],"alloy":[143],"redesign":[144],"or":[145],"additional":[146],"processing.":[148]}