To main content

How calcium prevents precipitation hardening in Al–Mg–Si alloys

Abstract

We have investigated the effect on precipitate microstructure and hardness upon adding small amounts of Ca to a base Al–Mg–Si alloy. The main investigative techniques were transmission and scanning electron microscopy. We found that large Ca-containing particles with composition CaAl2Si2 form during the production stages of the alloy. The particles leave less Si available in solid solution for the nucleation of hardening precipitates, leading to a coarser microstructure consisting of less coherent precipitates. The resulting hardness decrease is measurable for alloys containing more than 60 at ppm of Ca.
Read the publication

Category

Academic article

Language

English

Author(s)

Affiliation

  • SINTEF Industry / Materials and Nanotechnology
  • Norwegian University of Science and Technology

Year

2013

Published in

Materials Science & Engineering: A

ISSN

0921-5093

Volume

575

Page(s)

241 - 247

View this publication at Norwegian Research Information Repository