http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Fabricio A. Souza,Igor A. Magno,Marlo O. Costa,André S. Barros,Jacson M. Nascimento,Diego B. Carvalho,Otávio L. Rocha 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.1
Aluminum casting alloys have properties which are of great industrial interest, such as low density, good corrosion resistance,high thermal and electrical conductivities, good combination of mechanical properties, good workability in machiningprocesses and mechanical forming. Currently, these alloys are produced in various systems and dozens of compositions. Inthis investigation, a mutual interaction of thermal parameters, scale of the dendritic microstructure, intermetallic compounds(IMCs), microhardness and tensile properties/fracture characteristics of a casting Al–7wt%Si–3wt%Cu–0.3wt%Fe alloywas analyzed. Solidification experiments were developed using a furnace that promoted horizontal growth under transientheat flow conditions. Then, growth rate (VL), cooling rate (CR), and local solidification time (tSL) were determined frommeasured temperature profiles. Secondary dendritic spacings (λ2), Si particles, Fe-rich and Al2Cuintermetallic phases werecharacterized by optical and SEM microscopy, as well as the area mapping and point-wise EDS microanalysis. Hence, theinterrelations involving Vickers microhardness (HV), yield strength (σYS), ultimate tensile strength (σUTS) and elongation(E%) with microstructural features were evaluated by mathematical equations. IMCs as well as morphologies of Si were alsoanalyzed in the fracture regions. In addition, the experimental growth law of λ2 = f(tSL) proposed in this study was comparedwith a predictive theoretical model reported in the literature for multicomponent alloys. It was observed that areas that tendto grow faster (lowest λ2 values) were associated with the highest σUTS and E% values, while HV and σYS properties were notaffected by the thermal and microstructural parameters (CR and λ2). In addition, less extensive cleavage planes accompaniedby small dimples in were observed in fractured samples with lower λ2 values.