Chill modification in AI–Si–Sb eutectic alloys
Authors: Ourdjini, A.; Elliott, R.
Source: Materials Science and Technology, Volume 11, Number 12, December 1995 , pp. 1241-1245(5)
Publisher: Maney Publishing
Abstract:Interface undercooling and Si interparticle spacing measurements and observations of the Si phase structure are presented for Al–12·7Si–0·2Sb (wt-%) alloys directionally solidified over the growth velocity range 20–820 m S−1 with a temperature gradient in the liquid of 32 K cm−1. The undercooling measurements show that the undercooling decreases over the growth velocity range where chill modification occurs. Some cozonal twinning was observed in the fibres but the density of twinning decreased with increasing growth velocity and many fibres were observed to be twin free. The measured undercoolings and spacings are related to growth curves derived from the Jackson and Hunt analysis of eutectic growth, after allowance for a constitutional undercooling term due to Sb buildup at the growth interface during solidification. It is shown that the present measurements can be reconciled with a chill modification mechanism that assumes a faceted–non-faceted transition in the Si phase, but not with a mechanism that considers that the chill modified structure is a rapidly solidified flake structure.
Document Type: Research Article
Publication date: December 1995
- Materials Science and Technology is Journal of the Month in November. This means free online access to all of the last 3 years of content, including the most recently published 2013 articles! Find out more here
In 1985 Metal Science was incorporated into Material Science and Technology: See issues of Metal Science from 1985 to present. The archive also includes the complete run of Metals Technology (1974–84): Click here to see these issues.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Terms & Conditions
- Online submission site
- ingentaconnect is not responsible for the content or availability of external websites