High temperature mechanical behaviour of Mg–6Zn–1Y alloy with 1 wt.% calcium addition: Reinforcing effect due to I-(Mg3Zn6Y1) and Mg6Zn3Ca2 phases

The influence of small calcium additions on the high-temperature mechanical behaviour in an extruded Mg–6Zn–1Y (wt.%) alloy reinforced by the I-phase has been investigated. Calcium promotes the formation of the intermetallic MgZnCa phase instead of I-phase, which results in a noticeable improvement...

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Bibliographic Details
Authors: Medina, Judit, Garcés, Gerardo, Pérez Zubiaur, Pablo, Stark, Andreas, Schell, N., Adeva, Paloma
Format: article
Publication Date:2020
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/226027
Online Access:http://hdl.handle.net/10261/226027
Access Level:Open access
Keyword:Magnesium alloys
I-phase
Synchrotron radiation diffraction
High temperature mechanical properties
Description
Summary:The influence of small calcium additions on the high-temperature mechanical behaviour in an extruded Mg–6Zn–1Y (wt.%) alloy reinforced by the I-phase has been investigated. Calcium promotes the formation of the intermetallic MgZnCa phase instead of I-phase, which results in a noticeable improvement of the yield strength and ultimate tensile strength of the alloy above 100 °C. The strength of the alloys was analysed taking into account the contribution due to the grain size, the crystallographic texture and the volume fraction and nature of second phase particles. In situ synchrotron radiation diffraction experiments have been used to evaluate the load partitioning between the magnesium matrix and the second phase particles (I- and MgZnCa phases) in both alloys. The load transfer from the magnesium matrix towards the MgZnCa phase is markedly more effective than that for the I-phase over the entire temperature range, especially at 200 °C, temperature at which the reinforcement effect of the I-phase is null.