Analysis of Different Solution Treatments in the Transformation of β-AlFeSi Particles into α-(FeMn)Si and Their Influence on Different Ageing Treatments in Al–Mg–Si Alloys

Metals

Florentino Alvarez-Antolin¹  Alberto Cofiño-Villar¹  Alejandro Gonzalez-Pociño¹  Juan Asensio-Lozano¹ 

[1] Materials Pro Group, Department of Materials Science and Metallurgical Engineering, University of Oviedo, Independencia 13, 33004 Oviedo, Spain;

关键词: Al–Mg–Si;    -Al8(Fe2Mn)Si particles;    solution treatment;    ageing;    dissolution of Fe;    Differential Scanning Calorimetry;   

DOI  :  10.3390/met10050620

来源: DOAJ

【 摘 要 】

In the as-cast state, Al–Mg–Si alloys are not suitable for hot forming. They present low ductility due to the presence of intermetallic β-AlFeSi particles that form in the interdendritic regions during the solidification process. Homogenization treatments promote the transformation of these particles into -(FeMn)Si particles, which are smaller in size and more rounded in shape, thus improving the ductility of the material. This paper analyses the influence of various solution treatments on the transformation of β-AlFeSi particles into -(FeMn)Si particles in an Al 6063 alloy. Their effect on different ageing treatments in the 150–180 °C temperature range is also studied. An increase in the solution temperature favours greater transformation of the β-AlFeSi particles into -(FeMn)Si, dissolving a greater amount of Si, thereby having a significant effect on subsequent ageing. We found that as the dwell time at a temperature of 600 °C increases, the rate of dissolution of the Fe atoms from -(FeMn)Si particles exceeds the rate of incorporation of Mn atoms into said particles. This seems to produce a delay in reaching the peak hardness values in ageing treatments, which warrants further research to model this behaviour. The optimal solution treatment takes place at around 600 °C and the highest obtained peak hardness value is 104 HV after a 2 h solution treatment at said temperature and ageing at 160 °C for 12 h.

【 授权许可】

Unknown