WE43 + B₄C | Masih Banijamali

My deep dive into magnesium alloys kicked off with the ZK60+REE project—an exciting introduction to materials science that really got me hooked. That early success gave me the confidence (and curiosity) to take on bigger challenges. It also led to a new chapter in my academic journey: becoming a Graduate Research Assistant with the AMAs Research Group. That role opened up opportunities to explore even more advanced materials and experimental techniques.

The Research Focus:

Building on that momentum, I began working on a bold new project: developing a magnesium matrix composite aimed at improving performance in lightweight engineering applications. The core material? WE43 magnesium alloy, strengthened with different amounts of boron carbide (B₄C) particles. Unlike previous projects where I mostly studied existing alloys, this one asked me to take the wheel for the full ride—from designing and casting the composite to processing, testing, and analyzing it. It was a big leap, but also a great learning experience.

My Role:

My responsibilities spanned the entire development process. I worked on fine-tuning the stir casting technique, figuring out the best heat treatment conditions, and overcoming the complexities of hot rolling magnesium-based composites. On the analysis side, I led extensive testing—everything from optical microscopy and SEM-EDS to XRD and FTIR spectroscopy, plus mechanical tests for hardness, tensile strength, and wear behavior. The goal was to really understand how the B₄C additions and processing steps were affecting the material’s structure and performance.

Workflow for fabrication and analysis of WE43-B₄C magnesium composites.

It was a hands-on, problem-solving experience that pushed me to grow—not just technically, but also in terms of managing the project, staying organized, and working closely with others in the lab.

Outcomes and Publications:

The results were impressive. Adding B₄C particles and applying hot rolling led to major grain refinement in the WE43 matrix, which in turn boosted its performance. We also uncovered some fascinating details in the microstructure. In the hot-rolled matrix alloy without much reinforcement, twinning turned out to be the main deformation mechanism. But when we added more B₄C particles, the behavior shifted—dynamic recrystallization (DRX) took over, playing a key role in refining the structure. Another cool microstructural feature was the uniform, bimodal distribution of the B₄C particles in the matrix. This happened thanks to fragmentation of the coarse reinforcements during the rolling process, resulting in a well-dispersed mix of particle sizes. That kind of distribution is especially useful for balancing strength and ductility—always a great combo in structural materials.

Microstructure of hot-rolled WE43-x%B₄C composites; Size distribution of B₄C particles.

On the performance side, we saw increases of around 70% in hardness and 73% in strength with composites containing up to 10 wt% B₄C. Wear resistance also improved notably across all loading conditions, backed by both wear rate measurements and detailed worn surface analysis.

2D and 3D worn surface profiles of the WE43 alloy and WE43-10%B₄C composite under normal loads of 15, 30, and 90 N.

Interestingly, the impact of reinforcement on friction was load-dependent. Under low to moderate loads, friction either decreased or remained fairly steady even as wear rate dropped. But under high loads, friction actually increased—likely due to thermal softening or more intense plastic deformation at the contact surface. It was a good reminder that even tough materials can behave differently depending on the conditions they’re exposed to.

The correlation between the friction coefficient and the wear rate in magnesium composites.

We published two journal articles based on this work (Banijamali et al., 2022), (Banijamali et al., 2022), contributing new insights to the field of lightweight composite materials.

This project wasn’t just about results—it was about growth. I sharpened my experimental and analytical skills, learned to manage complex workflows, and gained a deeper understanding of how advanced composites work. Most of all, it reminded me how exciting it is to take an idea from concept to real-world impact.

In this study, WE43 alloy matrix composites, reinforced with 2.5, 5, 7.5, and 10 wt% B₄C particles have been produced by the stir casting technique at 750 °C. Cast ingots of the matrix alloy and the composites were then subjected to hot rolling at 480 °C. After that, the effect of B₄C additions (0–10 wt%) as well as hot rolling on the microstructure and mechanical properties of WE43 alloy were investigated. Microstructural characterization following hot rolling revealed a relatively uniform distribution of B₄C particles, well-bonded B₄C particles to the matrix, and a minimal porosity level. Further, both as-cast and hot-rolled composites have shown considerable grain refinement and hence improved mechanical properties compared to unreinforced alloy. Twinning was the dominant deformation mechanism in the hot-rolled WE43 alloy, whereas dynamic recrystallization occurred extensively in hot-rolled composites. It was observed that tensile strength and hardness values were improved not only as B₄C content increased but more due to the rolling effect; however, elongation to fracture was reduced. Maximum ultimate tensile strength of ∼284 MPa and yield strength of ∼259 MPa with an improved hardness to ∼97 HB were obtained for the hot-rolled WE43-10%B₄C composite.

This study aims to develop a novel hot-rolled WE43-B₄Cₚ composite with improved tribological performance for employment in the automotive industry. The pin-on-disc tribometer was used to evaluate the dry tribological behavior of newly developed composite materials containing (0-10) wt.% B₄C under various applied loads. It was observed that increasing B₄C content reduced the friction coefficient and significantly improved wear resistance in composite samples, especially at higher applied loads. With the addition of 10 wt% B₄C, the wear resistance of WE43 alloy was improved by around 25% at low load and 50% at high load regimes. The surface morphology and topography of the wear tracks were examined to identify the dominant wear mechanisms in each wear condition and reinforcement content. The dominant wear mechanisms at low loads were abrasion and slight oxidation, which were switched to adhesion and delamination as the applied load increased and thus to severe plastic deformation under high loads. The superior wear performance of the hot-rolled WE43-10%B₄Cₚ composite was ascribed to improved hardness and strength, as well as increased work hardening capacity of subsurface due to the presence of hard and thermally stable B₄C particles with uniform dispersion and proper bonding to the matrix.

The Research Focus:

My Role:

Outcomes and Publications:

References

2022