The rheocasting process applied by Swirled Enthalpy Equilibration Device (SEED) technique relies on rapid extraction of a controlled quantity of heat from the liquid aluminium alloy via mechanical agitation to form the semi-solid slurry that can be formed under pressure. Microstructural characteristics of both conventional and semi-solid A357 castings under T6 heat treatment conditions were examined using optical and scanning electron microscopy. The fatigue and tensile experiments were applied to evaluate the effect of SEED technique on the mechanical properties of T6-A357 semi-solid alloys and conventional castings. The results showed that the rheocasting–SEED technique has proved successful in producing optimum microstructure of Al–Si–Mg semi-solid alloys providing an excellent combination of quality and mechanical performance as compared to conventional technique.
This paper is part of a Themed Issue on Aluminium-based materials: processing, microstructure, properties, and recycling.
RossoM.: ‘The influence of casting process on quality and performances on Al based automotive components’, AMME13th Gliwice-Wista, Poland, 2005, 547–550.
2.
FridlyanderI. N., SisterV. G., GrushkoO. E., BerstenevV. V., ShevelevaL. M. and IvanovaL. A.: ‘Aluminum alloys: promising materials in the automotive industry’, Met. Sci. Heat Treat., 2002, 44, (9–10), 365–370. doi: 10.1023/A:1021901715578
3.
St JohnD., CaceresC., ZhangD., EdwardsG., TaylorJ. and SchafferG.: ‘Aluminum alloys for cast automotive components’, Materials in the automotive industry conference, Australia, 1996.
4.
SpadaA. T.: ‘In search of light-weight components: automotive's cast aluminum conversion’, Eng. Cast. Sol., 2002, 4, (2), 28–31.
5.
ShiozawaK., TohdaY. and SunS.-M.: ‘Crack initiation and small fatigue crack growth behaviour of Squeeze-cast Al–Si aluminum alloys’, Fatigue Fract. Eng. Mater. Struct., 1997, 20, (2), 237–247. doi: 10.1111/j.1460-2695.1997.tb00281.x
6.
DavidsonC. J., GriffithsJ. R. and MachinA. S.: ‘The effect of solution heat-treatment time on the fatigue properties of an Al–Si–Mg casting alloy’, Fatigue Fract. Eng. Mater. Struct., 2002, 25, (2), 223–230. doi: 10.1046/j.8756-758x.2001.00490.x
7.
ClossetB. and GruzleskiJ. E.: ‘Structure and properties of hypoeutectic Al–Si–Mg alloys modified with pure strontium’, Metall. Trans. A, 1982, 13, 945–951. doi: 10.1007/BF02643389
8.
TaylorJ. A., St JohnD. H. and CouperM. J.: ‘Solution treatment effects in Al–Si–Mg casting alloys: part II: solid solution chemistry’, Alum. Trans., 2001, 4–5, 111–124.
9.
WangQ. G. and DavidsonC. J.: ‘Solidification and precipitation behaviour of Al–Si–Mg casting alloys’, J. Mater. Sci., 2001, 36, 739–750. doi: 10.1023/A:1004801327556
10.
GustafssonG., ThorvaldssonT. and DunlopG. L.: ‘The influence of Fe and Cr on the microstructure of cast Al–Si–Mg alloys’, Metall. Trans. A, 1986, 17, 45–52. doi: 10.1007/BF02644441
11.
MorriA.: ‘Empirical models of mechanical behaviour of Al–Si–Mg cast alloys for high performance engine applications’, Metall. Sci. Technol., 2010, 28, (2), 2–8.
12.
DoutreD., LanglaisJ. and RoyS.: ‘The seed process for semi-solid forming’,
Proceedings of the 8th international conference on semi-solid processing of alloys and composites, Limassol, 2004.
13.
GanY. X. and OverfeltR. A.: ‘Fatigue property of semisolid A357 aluminum alloy under different heat treatment conditions’, J. Mater. Sci., 2006, 41, (22), 7537–44. doi: 10.1007/s10853-006-0838-5
14.
LanglaisJ. and LemieuxA.: ‘The SEED technology for semi-solid processing of aluminum alloys: a metallurgical and process overview’, Solid State Phenom., 2006, 116–117, 472–477.
15.
BergsmaS. C., LiX. and KassnerM. E.: ‘Semi-solid thermal transformations in Al–Si alloys: II. The optimized tensile and fatigue properties of semi-solid 357 and modified 319 aluminum alloys’, Mater. Sci. Eng. A, 2001, 297, (1), 69–77. doi: 10.1016/S0921-5093(00)01248-X
16.
BrochuM., VerremanY., AjerschF. and BouchardD.: ‘High cycle fatigue strength of permanent mold and rheocast aluminum 357 alloy’, Int. J. Fatigue, 2010, 32, (8), 1233–1242. doi: 10.1016/j.ijfatigue.2010.01.001
17.
CouperM. J., NeesonA. E. and GriffithsJ. R.: ‘Casting defects and the fatigue behaviour of an aluminium casting alloy’, Fatigue Fract. Eng. Mater. Struct., 1990, 13, (3), 213–27. doi: 10.1111/j.1460-2695.1990.tb00594.x
18.
WangQ. G., ApelianD. and LadosD. A.: ‘Fatigue behavior of A356-T6 aluminum cast alloys. Part I. Effect of casting defects’, J. Light Met., 2001, 1, (1), 73–84. doi: 10.1016/S1471-5317(00)00008-0
19.
PolmearI. J.: ‘Aluminium alloys-a century of age hardening’, Mater. Forum, 2004, 28, 1–14.
20.
PedersenL. and ArnbergL.: ‘The effect of solution heat treatment and quenching rates on mechanical properties and microstructures in Al-Si-Mg foundry alloys’, Metall. Mater. Trans. A, 2001, 32, (3), 525–532. doi: 10.1007/s11661-001-0069-y
21.
BergsmaS. C., KassnerM. E., EvangelistaE. and CerriE.: ‘The optimised tensile and fatigue properties of electromagnetically stirred and thermally transformed semi-solid 357 and modified 319 aluminium alloys’, Metall. Sci. Technol., 2000, 18, (2), 21–26.
22.
HornbogenE.: ‘Hundred years of precipitation hardening’, J. Light Met., 2001, 1, 127–132. doi: 10.1016/S1471-5317(01)00006-2
23.
CáceresC. H. and BarresiJ.: ‘Selection of temper and Mg content to optimize the quality index of Al-7Si-Mg casting alloys’, Int. J. Cast Met. Res., 2000, 12, (6), 377–384.
24.
RagabKh. A., SamuelA. M., Al-AhmariA. M. A., SamuelF. H. and DotyH. W.: ‘Effect of multi-temperature aging on the characterization of aluminum based castings heat treated using fluidized bed technique’, Met. Mater. Int., 2013, 19, (4), 783–802. doi: 10.1007/s12540-013-4019-1
25.
RagabKh. A., SamuelA. M., Al-AhmariA. M. A., SamuelF. H. and DotyH. W.: ‘Mechanical characterisation and quality index of A356-type aluminium castings heat treated using fluidised bed quenching’, Mater. Sci. Technol., 2013, 29, (4), 412–425. doi: 10.1179/1743284712Y.0000000124
26.
BouazaraM., BouaichaA., and RagabKh A.: ‘Fatigue characteristics and quality index of A357 type semi-solid aluminum castings used for automotive application.’ J. Mater. Eng. Perform., 2015, 24, (8), 3084–3092. doi: 10.1007/s11665-015-1602-2
27.
WickbergA., GustafssonG. and LarssonL.-E.: ‘Microstructure effects on the fatigue properties of a cast A17SiMg alloy’, SAE Trans., 1984, 93, 728–735.
28.
LampmanS. R.: ‘Fatigue and fracture’, 1996, ASM International, The Materials Information Society, Materials Park, OH, USA.
29.
HanS.-W., KumaiS. and SatoA.: ‘Effects of solidification structure on short fatigue crack growth in Al-7%Si-0.4%Mg alloy castings’, Mater. Sci. Eng. A, 2002, 332, 56–63. doi: 10.1016/S0921-5093(01)01713-0
30.
HayatN., TodaH., KobayashiT. and WadeN.: ‘Experimental investigations of fatigue characteristics of AC4CH cast aluminum alloys fabricated through Rheocast and Squeeze cast methods’, Mater. Sci. Forum, 2002, 396–402, 1353–58.
31.
DavidsonC. J., GriffithsJ. R., BadialiM. and ZanadaA.: ‘Fatigue properties of a semi-solid cast Al–7Si–0.3Mg–T6 alloy’, Metall. Sci. Technol., 2000, 18, (2), 27–31.
32.
BrochuM., VerremanY., AjerschF. and BucherL.: ‘Fatigue behavior of semi-solid cast aluminum: a critical review’, Solid State Phenom.: Diffus. Defect Data Part B, 2008, 141–143, 725–30.
33.
InceA. and GlinkaG.: ‘A modification of Morrow and Smith–Watson–Topper mean stress correction models’, Fatigue Fract. Eng. Mater. Struct., 2011, 34, (11), 854–867. doi: 10.1111/j.1460-2695.2011.01577.x
34.
SaoudiA., BouazaraM. and MarceauD.: ‘Study of fatigue life and weight optimization of automobile aluminum alloy part under random road excitation’, Shock Vib., 2010, 17, (2), 107–121. doi: 10.1155/2010/845609
35.
DrouzyM., JacobS. and RichardM.: ‘Interpretation of tensile results by means of quality index and probable yield strength’, Int. Cast Met. J., 1980, 5, (2), 43–50.
