July 20, 2021
Journal Article

Magnesium Alloy ZK60 Tubing made by Shear Assisted Processing and Extrusion (ShAPE)

Abstract

ZK60 Magnesium tubing has been friction extruded from as-cast billets and T5 conditioned bars using Shear Assisted Processing and Extrusion (ShAPE). Tubes having an outer diameter of 50.8 mm and wall thickness of 1.9 mm were extruded with >20 times less ram force compared to conventional extrusion due to the unique shearing conditions and tooling inherent to ShAPE. Microstructures of the as-cast billet and T5 bar feedstock materials were significantly different from each other in terms of grain size, texture, and second phase distribution; yet the resulting microstructures after ShAPE were remarkably similar. An average grain size of 4-5 microns, 20o tilt of basal texture away from the extrusion axis, and refined second phases having a uniform distribution were achieved independent of the feedstock material. Hardness for as-extruded and artificially aged tubes are presented with isotropic behavior explained by detailed microstructural analysis. This work suggests that bulk ZK60 magnesium alloys extrusions may be fabricated in a single step, with microstructures that are unobtainable with conventional extrusion.

Published: July 20, 2021

Citation

Whalen S.A., N.R. Overman, V.V. Joshi, T. Varga, D.D. Graff, and C.A. Lavender. 2019. "Magnesium Alloy ZK60 Tubing made by Shear Assisted Processing and Extrusion (ShAPE)." Materials Science and Engineering. A. Structural Materials: Properties, Microstructure and Processing 755. PNNL-SA-140301. doi:10.1016/j.msea.2019.04.013