Microstructural changes and thermal stability of a201, 319s and 2618 aluminum alloys during thermal exposure

Gao, Jun Zhen1,2; Zhu, Qiang3; Li, Da Quan1; Kang, Yong Lin2

10.4028/www.scientific.net/MSF.913.55

2018

0255-5476

MATER SCI FORUM

913

55-62

Yinchuan City, Ningxia, China

Trans Tech Publications Ltd

Turbocharger compressor wheels are often made of 3XX cast aluminum alloys and forged 2618 alloy. These age hardening aluminum alloys have high strength-to-weight ratio at ambient temperature. However, the strength of the aluminum alloys decreases rapidly when applied at high temperatures, such as for turbochargers where application temperature can be above 200 °C. The major reason is that the fine precipitated phases coarsen rapidly tending to their equilibrium states. The thermal stability of the 319s-T61, A201-T71 and 2618-T6 alloys were compared in this paper. The three alloys were exposed at 200 °C for 100 h during heat treatment. Hardness, tensile tests and TEM were carried out to investigate the mechanical properties and microstructure variation of these three alloys. The results indicated that the A201 alloy exhibited the best thermal stability among the three alloys and 319s alloy is the weakest one. TEM observation showed that with the increase of the exposure time, the strengthening precipitates phase θ′ in A201/319s alloys and S′ in 2618 alloy coarsened and then transformed to stable θ phase and S phase, respectively, while the primary strengthening phase Ω in A201 remained stable, which may be contributed the higher thermal stability of A201 than 319s and 2618.
© 2018 Trans Tech Publications, Switzerland.

通讯

EI

[2016YFB0301001]

20181104912239

Age hardening ; Heat treatment ; High strength alloys ; Mechanical properties ; Stability ; Superchargers ; Tensile testing ; Thermodynamic stability ; Turbomachinery

Metallurgy and Metallography:531 ; Metallurgy:531.1 ; Heat Treatment Processes:537.1 ; Aluminum Alloys:541.2 ; Thermodynamics:641.1 ; Materials Science:951

EV Compendex

1.General Research Institute for Nonferrous Metals, Beijing; 100088, China
2.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing; 100083, China
3.Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen; 518055, China

Gao, Jun Zhen,Zhu, Qiang,Li, Da Quan,et al. Microstructural changes and thermal stability of a201, 319s and 2618 aluminum alloys during thermal exposure[C]:Trans Tech Publications Ltd,2018:55-62.