Castings made from AI-Cu-Mg-Ag alloys have a high response to hardening in the artificially aged condition. This effect is considered to arise because silver changes the ageing process occurring in the equivalent ternary Al-Cu-Mg alloy and promotes precipitation of thin plates of a monoclinic form of the phase θ(CuAl2) on the {111} matrix planes. Replacing silver with cadmium also causes increased hardening, although the effect is less and arises from a refinement in the size of precipitates formed in the existing ageing process.
Get full access to this article
View all access options for this article.
References
1.
ILERA. J.: Met. Progr., 1969 (Jan.), p. 57.
2.
SPIEDELM. O.: Proc. 6th Int. Conf. ‘Light metals’, Leoben, Austria,1975, p. 67.
3.
MISRAM. S. and OSWALTK. J.: Met. Eng. Q., 1976, 16, 39.
4.
POLMEARI. J.: Trans. Metall. Soc. AIME, 1964, 1331.
5.
BABAY.: Trans. J. Inst. Met., 1965, 10, 188.
6.
AULDJ. H., VIETZJ. T., and POLMEARI. J.Nature, 1966, 209, 703.
7.
VIETZJ. T. and POLMEARI. J.: J. Inst. Met., 1966, 94, 410.
8.
SENN. and WESTD. R. F.: ‘The mechanism of phase transformations in crystalline solids’, p.49. 1969: London(Inst. Met.).
9.
SILCOCKJ. N.: J. Inst. Met., 1960 –61, 89, 203.
10.
AULDJ. H. and VIETZJ. T.: Ref. 8, p. 77.
11.
AULDJ. H.: Ada Cryst., 1972, 28A, 98.
12.
POLMEARI. J. and HARDYH. K.: J. Inst. Met., 1952 –3, 81, 427.
13.
SILCOCKJ. M., HEALT. J., and HARDYH. K.: ibid., 1953 –4, 82, 239.
