Sage Journals: Discover world-class research

Abstract

Evaluation of toughness in terms of the fracture energy E*, obtained using Charpy impact testing and the fracture toughness K_Ic obtained from bend tested specimens, has been carried out for various cast particle reinforced aluminium base composites, namely, A356–SiC, A357–SiC, 6061–Al₂O₃, and 2014–Al₂O₃. In practice, the first two are used in the as cast foundry condition and the last two in the cast and extruded condition. Hot extrusion or rolling to reduction ratios between 2 : 1 and 50: 1 was conducted on the 6061 and 2014 composites to characterise the influence of working processes. Heat treatment conditions considered included the as cast (or as worked), solid solution treated, and T6 temper. The results show that extrusion or rolling can markedly improve the toughness, but on thermal aging the toughness is reduced. The increase in total fracture energy by hot working is mainly caused by the increase of initiation energy, whereas the decrease of fracture energy by artificial aging is controlled by the propagation energy. The values of K_Ic obtained for these composites are from 15 to 25 MN m^−3/2. Comparisons and interpretations of the dynamic Charpy fracture energy, quasistatic fracture toughness, and fracture surface of the four composites are also presented.

MST/1806

Get full access to this article

View all access options for this article.

References

STEPHENS

J. J.

, LUCAS

J. P.

, and HOSKING

E M.

: Scr. Metall., 1988, 22, 1307–1312.

HAN

, POLLARD

, and STEVENS

: Mater. Sei. Technol., 1992, 8, 52–56.

KAMAT

S. V.

, HIRTH

J. H.

, and MEHRABIAN

: Acta Metall., 1989, 37, 2395-2402.

KALU

P. N.

and McNELLEY

T. R.

: Scr. Metall., 1991, 25, 853–858.

LEWANDOWSKI

J. J.

and LIU

: Mater. Sei. Eng., 1989, A107, 241–255.

FRIEND

C. M.

: Mater. Sei. Technol., 1989, 5, 1–7.

BARSOM

J. M.

and ROLFE

S. T.

: ‘Impact testing of metals’, STP 466, 281-288; 1970, Philadelphia, PA, ASTM.

ROBERTS

and NEWTON

: Bulletin 265, Welding Research Council, Cambridge, February 1981.

FERRY

, MUNROE

, CROSKY

, and CHANDRA

: Mater. Set. Technol., 1992, 8, 43–51.

10.

DAVIDSON

D. L.

: Metall. Trans., 1991, 22A, 113–123.

11.

WANG

and ZHANG

R. J.

: Metall. Trans., 1991, 22A, 1585–1593.

12.

‘Aluminum — properties and physical metallurgy’ (ed. Hatch

J. E.

); 1984, Metals Park, OH, ASM.

13.

KLIMOWICZ

T. E

and VECCHIO

R. S.

: in ‘Fundamental relation-ships between microstructures and mechanical properties of metal—matrix composites’, (ed. Liaw

P. K.

and Gungor

M. N.

), 255-267; 1990, Warrendale, PA, TMS.

14.

YOU

C. P.

, THOMPSON

A. W.

, and BERNSTEIN

I. M.

: Scr. Metall., 1987, 21, 181–185.

15.

MANOHARAN

and LEWANDOWSKI

J. J.

: Scr. Metall., 1989, 23, 301–304.

16.

MANOHARAN

and LEWANDOWSKI

J. J.

: Acta Metall., 1990, 38, 489–496.

17.

ADAMS

D. F.

: in Proc. 4th Conf. on ‘Composite materials: testing and design’, 409-426; 1977, STP 617, Philadelphia, PA, ASTM.

18.

NAKAGAWA

A. H.

and GUNGOR

M. N.

: in ‘Fundamental relationships between microstructures and mechanical prop-erties of metal—matrix composites’, (ed. Liaw

P. K.

and Gungor

M. N.

), 127-143; 1990, Warrendale, PA, TMS.

19.

McNELLEY

T. R.

and KALU

P. N.

: Scr. Metall., 1991, 25, 1041–1046.

20.

NIKLAS

, FROYEN

, and DELAEY

: Mater. Sci. Eng., 1991, A135, 225–229.

21.

FLOM

and ARSENAULT

R. J.

: Acta Metall., 1989, 37,2413–2423.

22.

HERTZBERG

R. W.

: ‘Deformation and fracture mechanisms of engineering materials’, 3 edn, 341; 1988, New York, Wiley.

23.

BLOYCE

and SUMMERS

J. C.

: Mater. Sei. Eng., 1991, A135, 231–236.

24.

HassoN

D. F.

and CROWE

C. R.

: in Proc. Conf. ‘Strength of metals and alloys’, 1515-1520; 1985, Oxford, Pergamon.

25.

HERTZBERG

R. W.

: ‘Deformation and fracture mechanisms of engineering materials’, 3 edn, 304; 1989, New York, Wiley.

Influence of heat treatment and hot working on fracture toughness of cast aluminium base composites

Abstract

Get full access to this article

References