Demirtas M.Purcek G.Yanar H.Zhang Z.J.Zhang Z.F.20.04.20192019-04-2020.04.20192019-04-2020150921-5093https://dx.doi.org/10.1016/j.msea.2015.07.041https://hdl.handle.net/20.500.12403/681Quasi-single phase (dilute) Zn-0.3Al alloy was subjected to severe plastic deformation via equal-channel angular extrusion/pressing (ECAE/P), and the effects of ECAP on its room temperature (RT) and high strain rate (HSR) superplasticity and deformation mechanism were investigated. Multi-pass ECAP may refine the coarse-grained microstructure into the fine grained (FG) one. The grain size of Zn-matrix phase decreased down to 2.0m after ECAP. Many spherical Al-rich precipitates decomposed and homogeneously distributed inside the matrix phase. They are ultrafine grained (UFG) ?-particles with the grain sizes ranging from 50nm to ~200nm. This special microstructure having FG and UFG micro-constituents brought about an improvement in RT superplasticity even at HSRs. While multi-pass ECAP decreased flow stress of the alloy, its elongation to failure increased substantially depending on the initial strain rates. The maximum elongation was 1000% at a low strain rate of 10-4s-1, and 350% elongation was achieved at a high strain rate of 10-2s-1. Grain boundary sliding (GBS) was found to be the main deformation mechanism in region-II as the optimum superplastic region. © 2015 Elsevier B.V..eninfo:eu-repo/semantics/closedAccessDilute Zn-Al alloysFine-grained microstructureRoom temperature superplasticitySevere plastic deformationAluminumElongationExtrusionGrain boundariesGrain boundary slidingGrain size and shapeMicrostructurePlastic deformationPressing (forming)Strain rateSuperplasticityZincDeformation mechanismEqual channel angular extrusionFine-grained microstructureGrain-boundary slidingsRoom-temperature superplasticitySevere plastic deformationsUltra-fine grained ( UFG)ZnAl alloyEqual channel angular pressingDilute Zn-Al alloysFine-grained microstructureRoom temperature superplasticitySevere plastic deformationAluminumElongationExtrusionGrain boundariesGrain boundary slidingGrain size and shapeMicrostructurePlastic deformationPressing (forming)Strain rateSuperplasticityZincDeformation mechanismEqual channel angular extrusionFine-grained microstructureGrain-boundary slidingsRoom-temperature superplasticitySevere plastic deformationsUltra-fine grained ( UFG)ZnAl alloyEqual channel angular pressingArticle644172410.1016/j.msea.2015.07.0412-s2.0-84937785869Q1WOS:000361258200003Q1