Enhancing the mechanical performances of friction stir lap welded Al-Zn-Mg-Cu alloy joint by promoting diffusion of alloying element Zn toward the pre-positioned Cu interlayer

In this study, large-sized Al–Zn–Mg–Cu alloy billets were prepared by direct chill casting imposed with annular electromagnetic stirring and intercooling; a process named uniform direct chill casting. The effects of uniform direct chill casting on grain size and the alloying element distribution of the billets were investigated and compared with those of the normal direct chill casting method. The results show that the microstructures were refined and the homogeneity of the alloying elements distribution was greatly improved by imposing the annular electromagnetic stirring and intercooling. In uniform direct chill casting, explosive nucleation can be triggered, originating from the mold wall and dendrite fragments for grain refinement. The effects of electromagnetic stirring on macrosegregation are discussed with consideration of the centrifugal force that drives the movement of melt from the central part towards the upper-periphery part, which could suppress the macrosegregation of alloying elements. The refined grain can reduce the permeability of the melt in the mushy zone that can restrain macrosegregation.

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Effects of friction-stir processing with water cooling on the properties of an Al–Zn–Mg–Cu Alloy

Materials Science and Technology ◽

10.1080/02670836.2017.1366709 ◽

2017 ◽

Vol 34 (2) ◽

pp. 153-160 ◽

Cited By ~ 10

Author(s):

Yu Chen ◽

Yifu Jiang ◽

Hua Ding ◽

Jingwei Zhao ◽

Jizhong Li

Keyword(s):

Friction Stir Processing ◽

Water Cooling ◽

Friction Stir ◽

Cu Alloy

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Effect of multi-pass friction stir processing on microstructural, mechanical and tribological behaviour of as-cast Al–Zn–Mg–Cu alloy

Materials Research Express ◽

10.1088/2053-1591/ab308c ◽

2019 ◽

Vol 6 (9) ◽

pp. 096579 ◽

Cited By ~ 3

Author(s):

Rabindra Prasad ◽

S P Tewari ◽

J K Singh

Keyword(s):

Friction Stir Processing ◽

Tribological Behaviour ◽

Friction Stir ◽

Cu Alloy

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Influence of Grain Coarsening on the Creep Parameters During the Superplastic Deformation of a Severely Friction Stir Processed Al-Zn-Mg-Cu Alloy

Metallurgical and Materials Transactions A ◽

10.1007/s11661-017-4198-3 ◽

2017 ◽

Vol 48 (9) ◽

pp. 3980-3984 ◽

Cited By ~ 3

Author(s):

Alberto Orozco-Caballero ◽

Oscar A. Ruano ◽

Fernando Carreño

Keyword(s):

Superplastic Deformation ◽

Grain Coarsening ◽

Friction Stir ◽

Cu Alloy

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Microstructure and Mechanical Properties of a Friction Stir Processed Al-Zn-Mg-Cu Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.654-656.1428 ◽

2010 ◽

Vol 654-656 ◽

pp. 1428-1431 ◽

Cited By ~ 1

Author(s):

Margarita Vargas ◽

Sri Lathabai

Keyword(s):

Mechanical Properties ◽

Rotational Speed ◽

High Strength ◽

Travel Speed ◽

Nugget Zone ◽

Friction Stir ◽

Complex Interactions ◽

Cu Alloy ◽

Microstructure And Mechanical Properties ◽

Aa 7075

Friction stir processing (FSP) was performed on AA 7075-T6, a heat treatable high strength Al-Zn-Mg-Cu alloy. The two main FSP parameters, the tool rotational and travel speed, were varied systematically in order to understand their influence on the microstructure and mechanical properties of the processed zone. At a given rotational speed, increasing the travel speed increased the microhardness of the nugget (stir) zone; for a given travel speed there appeared to be an optimum rotational speed which resulted in the highest microhardness. The range of FSP parameters used did not significantly influence the nugget zone grain size. It is suggested that the observed mechanical properties are a result of the complex interactions between the FSP thermo-mechanical effects and the processes of dissolution, coarsening and re-precipitation of the strengthening precipitates in this alloy.

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