Effect of the Shape of Rolling Passes and the Temperature on the Corrosion Protection of the Mg/Al Bimetallic Bars.

Sebastian Mróz,Andrzej Stefanik,Robert Kosturek,Marcin Wachowski,Karina Jagielska-Wiaderek,Piotr Szota

doi:10.3390/ma14226926

Sebastian Mróz, Andrzej Stefanik + Show 4 more

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https://doi.org/10.3390/ma14226926

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Abstract

The paper presents the results of experimental tests of the rolling process of Mg/Al bimetallic bars in two systems of classic passes (horizontal oval-circle-horizontal oval-circle variant I) and modified (multi-radial horizontal oval-multi-radial vertical oval-multi-radial horizontal oval-circle-variant II). The feedstock in the form of round bimetallic bars with a diameter of 22 mm and 30% of the outer aluminum layer was made through explosive welding. The bimetallic bars consisted of an AZ31 magnesium core and a 1050A aluminum outer layer. Bars with a diameter of 17 mm were obtained as a result of rolling in four passes. The rolling process in the passes was conducted at two temperatures of 300 and 400 °C. Based on the analysis of the test results, it was found that the use of modified passes and a lower rolling temperature (300 °C) ensures a more homogenous distribution of the plating layer around the circumference of the core and results in an even grain decreasing, which improves the corrosion resistance of bimetallic bars compared to rolling bars in a classic system of passes and at a higher temperature (400 °C).

Highlights

Products made of magnesium alloys have been drawing more and more attention in many industries for over a dozen years
One of the methods ensuring the improvement of corrosion resistance of magnesium alloys is laser surface alloying [7,12] and thermo-chemical treatment [13], which are commonly used techniques for producing layers enriched in Al
A more even deformation in the Al plating layer resulting from the deformation method and the reduced temperature results in an even grain fragmentation, which improves the corrosion resistance of bimetallic bars

Summary

Introduction

Products made of magnesium alloys have been drawing more and more attention in many industries for over a dozen years. One of the methods ensuring the right thickness and even distribution on the perimeter of the round bar of the plating layer is the combination of the explosive welding method to produce a bimetallic feedstock, and rolling in elongating grooves [32,33].

Results

Conclusion