MS13-P03 Structural investigation of the phase transition in the 18-carat gold alloy starting from the disordered state Imene Lamiri (Physica y Analitica Chimica, Oviedo, Spain) Mohammed S.M. Abdelbaky (Physica y Analitica Chimica, Oviedo, Spain) Santiago García Granda (Physica y Analitica Chimica, Oviedo, Spain) Djamel Hamana (Physics, Constantine, Algeria)email: imene.lamiri@umc.edu.dzPhase transition sequences in gold alloys haveattract a lot of interest at the first half of the 20Th century. Where, till now the thorough sequences ant the temperatures are not investigated. The knowing of such precise temperatures and sequences is of high importance according to the gold alloys industrial use [1-3].Herein,In-situ temperature XRD and mechanical spectroscopy were applied to study phase transitions in AuCu alloy. The phase transition sequences, with the disorder as starting state for the thermal cycle, was investigated upon heating and cooling using heating rate of 1K/min. The sequences of phase transitions recorded show an important succession at continuous heating and subsequent cooling. The transition temperatures were thoroughly determined. This transition sequences determine temperature dependency of elastic and anelastic properties. The mechanical spectroscopy using forced torsion pendulum shows twin boundaries peak as typical peak of the orthorhombic phase AuCuII and transient peak with the onset of the tetragonal AuCuI in A1 phase with the classical Zener peak.
Aknoweldgment:Financial support from the Algerian Ministry of Higher Education and Scientific Research (PNE scholarship),Spanish Ministerio de Economía y Competitividad(MAT2016-78155-C2-1-R and FPI grant BES-2011-046948 to MSM.A.) and Gobierno del PrincipadodeAsturias (GRUPIN14-060)are acknowledged.

 
References:

[1] A. K. Maier, I. Tkalcec, D. Mari, R. Schaller, Mater. Sci. Eng., A. 560 (2013) 466-472.

[2] I. Tkalcec, D. Mari, R. Schaller, Archives of Metallurgy and Materials. 60 (2015), 0353.

[3] J. Hennig, D. Mari, R. Schaller, Phys. Rev. B. 144 (2009) 116-79.

Keywords: Gold alloys, in-situ temperature XRD, mechanical spectroscopy