A multi modal approach to microstructure evolution and mechanical response of additive friction stir deposited AZ31B Mg alloy

Abstract

Current work explored solid-state additive manufacturing of AZ31B-Mg alloy using additive friction stir deposition. Samples with relative densities ≥ 99.4% were additively produced. Spatial and temporal evolution of temperature during additive friction stir deposition was predicted using multi-layer computational process model. Microstructural evolution in the additively fabricated samples was examined using electron back scatter diffraction and high-resolution transmission electron microscopy. Mechanical properties of the additive samples were evaluated by non-destructive effective bulk modulus elastography and destructive uni-axial tensile testing. Additively produced samples experienced evolution of predominantly basal texture on the top surface and a marginal increase in the grain size compared to feed stock. Transmission electron microscopy shed light on fine scale precipitation of Mg$$_{17}$$ 17 Al$$_{12}$$ 12 within feed stock and additive samples. The fraction of Mg$$_{17}$$ 17 Al$$_{12}$$ 12 reduced in the additively produced samples compared to feed stock. The bulk dynamic modulus of the additive samples was slightly lower than the feed stock. There was a $$\sim\,$$ ∼ 30 MPa reduction in 0.2% proof stress and a 10–30 MPa reduction in ultimate tensile strength for the additively produced samples compared to feed stock. The elongation of the additive samples was 4–10% lower than feed stock. Such a property response for additive friction stir deposited AZ31B-Mg alloy was realized through distinct thermokinetics driven multi-scale microstructure evolution.

Tailored Surfaces on Biomedical Magnesium Alloys via Novel Beam and Friction Based Manufacturing Processes: A Review

“…Similar reduction in properties was reported in the case of AZ31B Mg alloy [104] and subsequent efforts by separate set of authors [105,106] examined the reasons behind such a reduction. It was reported that deposition of a single layer can result in deposition of a refined grain material as a result of dynamic recrystallization.…”

“…Fig 29. Spatial and temporal variation during additive friction stir deposition of AZ31B Mg alloy plotted in a and b for two different processing conditions[106] …”

Solid-State VS. Fusion-Based Metal Additive Manufacturing Technologies

“…Yoder et al (Yoder et al, 2021), compared the properties of as-built AA 7075 with the as-wrought feedstock. Joshi et al (Joshi et al, 2022) investigated AFSD of AZ31B and Williams et al (Williams et al, 2021) tested WE43 Mg alloy and obtained a refined, homogenous equiaxed microstructure when compared to the feedstock resulting in a reduction in average grain size from 45 to 2.7 µm on the top layer and 4.5 µm on the bottom one. Griffith et al (Griffiths et al, 2022) tested the feasibility of AFSD of stainless steel 304 under water and showed good deposition quality and remarkable microstructure differences from conventional deposition.…”

The Effects of Layer Thickness on the Mechanical Properties of Additive Friction Stir Deposition-Fabricated Aluminum Alloy 6061 Parts

“…The deposition of parts made of other metal alloys is also reported in the literature. Various aspects of AFSD-fabricated parts made with Titanium alloy [26,42], magnesium alloy [2,[43][44][45], Inconel alloy [46,47], stainless steel [48][49][50], copper alloy [51], and also high-entropy alloy (HEA) [52] are studied in the literature.…”