Deformation and fracture of dispersion-strengthened high-temperature Al-8. 5 Fe-1. 3 V-1. 7 Si alloy

Abstract

The fracture behavior of Al-8. 5Fe-1. 3V-1. 7Si (mass fraction,%) alloy under different deforming conditions was investigated. The results show that the propagation mode of the main crack was correlated with the orientation of prior powder boundaries (PPB’s) when the specimen ruptured. For the L-direction tensile specimen, the LT-oriented microcrack along PPB’s didn’t affect the main crack’s extension; the LS-oriented microcrack might lead to unusual failure; the TS-oriented boundary was ready to become the low-energy propagating path for the main crack. Hot rolling resulted in a larger increase of the cohesion strength of LS-and TS-oriented boundaries than that of LT-oriented boundary, thus causing the corresponding change of fracture mode at a certain deformation amount (30%). The different variation tendency for fracture strength and elongation arised from this change of fracture mode and subsequent work hardening.

Keywords

rapid solidification / heat-resistant aluminium alloy / fracture

References

[1] SkinnerD J, ByeR L, RayhouldD. Dispersion strengthened Al-Fe-V-Si alloys. Scripta Metall, 1986, 20(6): 867-867

[2] FrankR E, HawkJ A. Effect of very high temperature on the mechanical properties of Al-Fe-V-Si alloys. Scripta Metall, 1989, 23(1): 113-113

[3] Skineer D J. The physical metallurgy of dispersion strengthened Al-Fe-V-Si alloys. In: Kim Y W, Griffith W M eds. Dispersion Strengthened Aluminum Alloys, MMMS, 1988. 181

[4] MitraS. Elevated temperature mechanical properties of a rapidly solidified Al-Fe-V-Si alloy. Scripta Metall, 1992, 27(5): 521-521

[5] LeeS, LeeD, LeeD Y. Microstructure and fracture properties of dispersion strenghtened high temperature Al-8. 5Fe-1. 2V-1. 7Si alloys. Mater Sci and Eng, 1991, 43: 33-33

[6] LeeJ C, LeeS, LeeD Y. On the embrittlement of a rapidly solidified Al-Fe-V-Si alloy after high-temperature exposure. Metall Trans, 1991, 22A: 853-853

[7] HariprasadS. Fatigue crack growth rates and fracture toughness of rapidly solidified Al-8. 5pctFe-1. 2pctV-1. 7pct Si alloys. Metall and Mater Trans, 1994, 25A: 1005-1005

[8] Chen Z H, Jiang X Y, Wang Y, et al. A multi-stage atomization rapid solidification powder-making device. CN88212137·5, 1988

[9] ChanK S. Evidence of a thin sheet toughening mechanism in Al-Fe-X alloys. Metall Trans, 1989, 20A: 155-155

[10] ChanK S. Confirmation of a thin sheet toughening mechanism and anisotropic fracture in Al-Fe-X alloys. Metall Trans, 1989, 20A: 2337-2337

[11] KimY W, GriffithW M, TroesF H. Surface oxides in P/M aluminum alloys. J Met, 1985, 8: 27-27