Sage Journals: Discover world-class research

Abstract

The effect of grain boundary orientation on the creep behaviour of a directionally solidified nickel base superalloy (CM 247 LC alloy) has been studied at 1123 K in the stress range 400–500 MN m⁻². The variation of minimum creep rate with orientation in the alloy can be related to anisotropic slip and early onset of tertiary creep in specimens with inclined boundaries. Transgranular fracture in longitudinal specimens occurred by crack like cavity growth along γ–γ′ rafts which developed in the initial stages of creep deformation. In specimens with inclined boundaries, intergranular fracture occurred by cracklike void growth and power law creep may have made a significant contribution to the growth of voids.

MST/2097

Get full access to this article

View all access options for this article.

References

HARRIS

, ERICKSON

G. L.

, and SCHWER

R. E.

: in Superalloys 1984’, (ed. M. Gell et al.), 221-230; 1984, Champion, PA, The Metallurgical Society of AIME.

ERICKSON

G. L.

, HARRIS

, and SCHWER

R. E.

: in Proc. 30th Int. Conf. on ‘Gas turbines’, 17-21; 1985, NY, American Society of Mechanical Engineers.

MONKMAN

F. C.

and GRANT

N. J.

: Proc. Am. Soc. Test. Mater., 1956, 56, 593.

DOBES

F DOBES.

K. miLibc.A: Met. Sci., 1976, 10, 382–384.

F.B. and McLEAN

: Acta Metall., 1983, 31, 17–27.

CARON

, OHTA

, NAKAGAWA

Y. G.

, and KHAN

: in ‘Superalloys 1988’, (ed. S. Reichman et al.), 215-224; 1988, Champion, PA, The Metallurgical Society of AIME.

S. H.

, LUPIC

, and MALDINI

: Scr. Metall. Mater., 1992, 26, 579–584.

BROWN

L. M.

and EMBURY

J. D.

: in Proc. 3rd Int. Conf. on ‘Strengths of metals and alloys’, Vol. 1, 164-169; 1973, London, The Institute of Metals.

ASHBY

M. F.

and DYSON

B. F.

: in Proc. ‘Advances in fracture research’, (ed. Valluri

S. R.

et al.), Vol. 1, 3–30; 1984, Oxford, Pergamon Press.

10.

BEERE

and SPEIGHT

M. V.

: Met. Sci., 1978, 12, 172–176.

11.

EDWARD

G. H.

and ASHBY

M. F.

: Acta Metall., 1979, 27, 1506–1518.

12.

Como

A. C. F.

and ASHBY

M. F.

: Met. Sci., 1980, 14, 395–402.

13.

NEEDLEMAN

and RICE

J. R.

: Acta Metall., 1980, 28, 1315–1332.

14.

COCKS

A. C. F.

and ASHBY

M. F.

: Met. Sci., 1982, 16, 465–474.

Effect of grain boundary orientation on creep behaviour of directionally solidified nickel base superalloy (CM 247 LC alloy)

Abstract

Get full access to this article

References