HAMILTA DE OLIVEIRA SANTOS

HAMILTA DE OLIVEIRA SANTOS

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Corrosion behaviour of hypereutectic Al-Si-Cu alloys used in cylinder liners
2005 - SANTOS, H.O.; KUNIOSHI, C.T.; ROSSI, J.L.; COSTA, I.; REIS, F.M.
In this study, the corrosion resistance of four Al-Si hypereutectic alloys has been investigated in a solution of chemical composition typical of the condensed solution from automotive fuel combustion products - here named automotive synthetic condensed solution. The significance of the undertaken study was in the evaluation of materials used for cylinder liners fabrication in relation to the Brazilian motor fuel. Three commercial Al-Si alloys that have been used for cylinder liners and a laboratory made alloy (Osprey Process) were evaluated by electrochemical impedance spectroscopy measurements at increasing times of immersion in this solution. The surfaces of the alloys were evaluated before and after corrosion test by scanning electron microscopy and. Although the corrosion mechanisms present similarities for all the commercial alloys investigated, the results also indicated different corrosion resistances for these alloys, and these were related to their microstructure characteristics. The laboratory prepared alloy showed increased susceptibility to pitting corrosion comparatively to the commercial alloys.
Scanning electron microscopy studies of Fe- 3 percent Si texture obtained by etch-pit method
1998 - SANTOS, H.O.; MONTEIRO, W.A.; RODRIGUES, V.A.; LIMA, N.B.
Microstructural characterization of spray formed alloys for cylinder liners
2001 - SANTOS, H.O.; COSTA, I.; ROSSI, J.L.
Ligas de aluminio-silicio conformadas por 'spray' - influência da laminação
2006 - SANTOS, H.O.; MARTINEZ, L.G.; COSTA, I.; ROSSI, J.L.
Caracterizacao do comportamento de corrosao de ligas hipereuteticas Al-Si
2010 - SANTOS, H.O.; KUNIOSHI, C.T.; ROSSI, J.L.; COSTA, I.
X-ray determination of crystal alignment in Pr-Fe-B sintered magnets produced from hydride powder and from partially and totally desorbed hydride powder
1994 - LIMA, N.B.; SERNA, M.M.; SANTOS, H.O.; FARIA JUNIOR, R.N.; WILLIAMS, A.J.; HARRIS, I.R.
Crystallographic orientation study of spray formed hypereutectic Al-Si alloys used in the automotive industry
2003 - SANTOS, H.O.; LIMA, N.B.; COSTA, I.; ROSSI, J.L.; SANTOS, J.C.; COLOSIO, M.A.
Ligas de aluminio hipereuteticas conformadas por spray - orientacao cristalografica
2003 - SANTOS, H.O.; SERNA, M.M.; JESUS, S.L.; LIMA, N.B.; COSTA, I.; ROSSI, J.L.
Corrosion performance of Al-Si-Cu hypereutectic alloys in automotive synthetic condensed solution
2003 - SANTOS, H.O.; REIS, F.M.; KUNIOSHI, C.T.; ROSSI, J.L.; COSTA, I.
Spray formed hypereutectic aluminium alloys - crystallographic orientation
2003 - SANTOS, H.O.; SERNA, M.M.; LIMA, N.B.; COSTA, I.; ROSSI, J.L.
Hypereutectic aluminium-silicon alloys have been wide accepted in the automotive, electric and aerospace industries. This is due to the high strength-weight ratio, to the low coefficient of thermal expansion and the good resistance to the wear and tear. The use of conventional metallurgy for production of these alloys is limited by a narrow range of possible compositions. This can be attributed to the formation and presence of coarse primary silicon particles, because of the slow cooling rate associated to conventional metallurgy. The use of spray forming can overcome this obstacle. The present work was undertaken to analyse the texture by X-ray diffraction techniques of three spray formed aluminium-silicon alloys. One experimental alloy (alloy 1) was hot-rolled and cold-rolled. 'The other two alloys are in commercial use, alloys 2 and 3. The results from the Laue camera showed texture just in the axial direction of alloy 3. The pole figures also indicated the presence of deformation texture just for alloy 3.