The principal failure mechanism in thixoforming dies is expected to be thermal fatigue, as the mechanical loading on tooling is modest owing to a semisolid feedstock. High process temperatures during steel thixoforming induce high compressive strains at the die cavity surface during slurry injection. The magnitudes of the thermal gradient and strains that develop on the cavity surface are directly linked with the temperature of the die surface immediately before slurry injection. An increase in die bulk temperature from 450 to 550°C reduces the surface to interior temperature differential and thus the surface strains by as much as 30%, a very favourable effect from thermal fatigue point of view.
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References
1.
GaratM.BlaisS.PluchonC.LoueW. R.BhasinA. K.MooreJ. J.YoungK. P.MidsonS.: Proc. 5th Int. Conf. on ‘Semisolid processing of alloys and composites’, Golden, CO, USA, June 1998, Colorado School of Mines, 17.
2.
BobzinK.LugscheiderE.MaesM.ImmichP.: Solid State Phenom., 2006, 116–117, 704–709.
3.
FlemingsM. C.: Proc. 6th Int. Conf. on ‘Semi-solid processing of alloys and composites’, (ed. ChiarmettaG. L.RossoM.), Turin, Italy, September2000, 11–14.
4.
KoppR.KallweitJ.MollerT.SeidlI.: J. Mater. Process. Technol., 2002, 130, 562–568.
5.
BehrensB.-A.HallerBFischerD.: Proc. 8th Int. Conf. on ‘Semi-solid processing of alloys and composites’, (ed. ApelianD.AlexandrouA.), Limasol, Cyprus, September2004, NADCA/University of Cyprus.
6.
BirolY.: Steel Res. Int., 2009, 80, 165–171.
7.
MuenstermannS.UibelK.TonnesenT.TelleR.: Solid State Phenom., 2006, 116–117, 696–699.
LugscheiderE.HornigTh.D.KyrylovO.PrangeR.: Proc. 6th Int. Conf. on ‘Semi-solid processing of alloys and composites’, (ed. ChiarmettaG. L.RossoM.), Turin, Italy, September2000, 587–592.
10.
TelleR.MuenstermannS.BeyerC.: Solid State Phenom., 2006, 116–117, 690–695.
11.
BirolY.: Solid State Phenom., 2008, 141–143, 289–294.
12.
KapranosP.KirkwoodD. H.SellarsC. M.: Proc. 4th Int. Conf. on ‘Semi-solid processing of alloys and composites’, Sheffield, UK, June 1996, University of Sheffield, 306.
13.
KoppR.LugscheiderE.HornigT.KallweitJ.MaesM.SeidlI.: Proc. 5th Int. ESAFORM Conf. on ‘Material forming’, Krakow, Poland, April 2002, Akapit, 659.
PetersD. T.BrushE. F.CowieJ. G.MidsonS. P.: ‘Die casting toward the future’, T02–065;2002, Wheeling, IL, North American Die Casting Association.
16.
RileyF. L.: J. Am. Ceram. Soc., 2000, 83, 245.
17.
SchwamD.WallaceJ. F.BircenauS.: ‘Die materials for critical applications and increased production rates’, DE-FC07–98ID13693, USDOE, Washington, DC, USA, 2002.
18.
BirolY.: Steel Res. Int., DOI 10.2374/SRI08SP130.
19.
HermanE. A.WallaceJ. F.MachonisA. A.: ‘Copper alloy pressure die casting’, 52; 1975, New York, International Copper Research Association.
20.
DoehlerH. H.: ‘Die casting’, 163–165; 1951, New York, McGraw-Hill.
21.
PetersD. T.CowieJ. G.BrushE. F.Jr: Proc. Conf. EEMODS ’99, London, UK, September 1999, EC.
