Impression creep behaviour of magnesium alloy-based hybrid composites in the transverse direction


Autoria(s): Mondal, AK; Kumar, S
Data(s)

01/08/2009

Resumo

The creep behaviour of a creep-resistant AE42 magnesium alloy reinforced with Saffil short fibres and SiC particulates in various combinations has been investigated in the transverse direction, i.e., the plane containing random fibre orientation was perpendicular to the loading direction, in the temperature range of 175-300 degrees C at the stress levels ranging from 60 to 140 MPa using impression creep test technique. Normal creep behaviour, i.e., strain rate decreasing with strain and then reaching a steady state, is observed at 175 degrees C at all the stresses employed, and up to 80 MPa stress at 240 degrees C. A reverse creep behaviour, i.e., strain rate increasing with strain, then reaching a steady state and then decreasing, is observed above 80 MPa stress at 240 degrees C and at all the stress levels at 300 degrees C. This pattern remains the same for all the composites employed. The reverse creep behaviour is found to be associated with fibre breakage. The apparent stress exponent is found to be very high for all the composites. However, after taking the threshold stress into account, the true stress exponent is found to range between 4 and 7, which suggests viscous glide and dislocation climb being the dominant creep mechanisms. The apparent activation energy Q(C) was not calculated due to insufficient data at any stress level either for normal or reverse creep behaviour. The creep resistance of the hybrid composites is found to be comparable to that of the composite reinforced with 20% Saffil short fibres alone at all the temperatures and stress levels investigated. The creep rate of the composites in the transverse direction is found to be higher than the creep rate in the longitudinal direction reported in a previous paper.

Formato

application/pdf

Identificador

http://eprints.iisc.ernet.in/21659/1/sdarticle.pdf

Mondal, AK and Kumar, S (2009) Impression creep behaviour of magnesium alloy-based hybrid composites in the transverse direction. In: Composites Science and Technology, 69 (10, Sp). pp. 1592-1598.

Publicador

Elsevier Science

Relação

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWT-4VV2NNV-1&_user=512776&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000025298&_version=1&_urlVersion=0&_userid=512776&md5=531cd9dfd751b71ecf45e5f18df8bb8d

http://eprints.iisc.ernet.in/21659/

Palavras-Chave #Materials Engineering (formerly Metallurgy)
Tipo

Journal Article

PeerReviewed