Par Gargee Dash, M.Sc. en génie des matériaux de l’Université de McGill
Lorsque le magazine Al13 nous a proposé de participer à son numéro spécial « Je lis la science », toute l’équipe du Centre de recherche sur l’aluminium REGAL a accepté avec enthousiasme. Cette initiative nous offre une belle occasion de faire rayonner la diversité des sujets de recherche et le dynamisme de notre communauté étudiante.
Au cours des prochaines semaines, vous pourrez découvrir des étudiantes et des étudiants animés par la curiosité scientifique et passionnés par toute la richesse du monde universitaire québécois. À travers leurs travaux, ils contribuent de manière remarquable à l’avancement des connaissances et des technologies dans le domaine de l’aluminium.
Nous débutons en force avec un texte qui illustre à merveille la façon dont peut naître une passion pour la recherche, à travers les mots de Gargee Dash, récemment diplômée à la maîtrise de l’Université McGill.
Houshang Alamdari
Directeur du Centre de recherche sur l’aluminium REGAL
Professeur titulaire
Département de génie des mines, de la métallurgie et des matériaux, Université Laval
[FR] Gargee Dash a récemment obtenu sa maîtrise en génie des matériaux à l’Université McGill et travaille comme adjointe de recherche dans le domaine des alliages d’aluminium et de la fabrication additive. Elle a reçu le Prix d’excellence des études supérieures de McGill, ainsi que les bourses Horace Young, Sir William Dawson, Women in Aerospace et Mario Fafard. En dehors de ses activités de recherche, elle aime faire de l’équitation.
[EN] Gargee Dash recently completed her M.Sc. in Materials Engineering at McGill University and works as a Research Assistant in aluminium alloys and additive manufacturing. She has received the McGill Graduate Excellence Award, Horace Young, Sir William Dawson, Women in Aerospace, and Mario Fafard scholarships. Outside research, she enjoys horse riding.
Résumé en français
Enfant, en regardant les films Iron Man, je n’étais pas seulement fascinée par le héros, mais surtout par son armure. Elle représentait pour moi la combinaison parfaite de légèreté, de résistance, de protection et de performance. Sans encore connaître le vocabulaire de l’ingénierie ou de la science des matériaux, je me demandais déjà ce qui pouvait rendre un matériau aussi fort, fiable et adaptable.
Mon parcours a commencé en génie mécanique, où j’ai appris à comprendre les structures, les forces, les machines et les modes de rupture. Peu à peu, mon attention s’est déplacée vers ce qui se cache derrière chaque composant : le matériau lui-même. J’ai découvert que les matériaux ne sont pas de simples substances utilisées pour fabriquer des objets, mais qu’ils déterminent directement ce que ces objets peuvent devenir.
Aujourd’hui, dans le cadre de ma maîtrise en génie des matériaux à l’Université McGill, j’étudie des alliages d’aluminium fabriqués par fabrication additive métallique, notamment par fusion laser sur lit de poudre. Mon projet porte sur l’alliage F357, un alliage aluminium-silicium-magnésium, et sur son évolution après traitement thermique et exposition prolongée à température élevée.
À l’échelle microscopique, l’aluminium imprimé en 3D contient des particules de silicium, des précipités durcissants, des cellules d’aluminium et des interfaces qui influencent directement ses propriétés mécaniques. Mon travail vise à comprendre comment ces caractéristiques évoluent avec le temps et la chaleur, et comment elles affectent la dureté, la résistance, la ductilité et le comportement à la rupture.
Pour moi, « lire la science », c’est apprendre à lire le langage caché des matériaux : une particule, une surface de rupture et une microstructure à la fois.
Full version in English – I Wanted to Be the Suit
When I was a child, I watched Iron Man with complete fascination.
Like many children, I was amazed by the flying, the glowing arc reactor, the action, and the impossible technology. But I remember being drawn to something different.
I did not just want to be Iron Man.
I wanted to be the suit.
To me, the suit was the real miracle. It was light but strong. Protective but flexible. It could survive impact, heat, damage, and still return to the sky: it was sustainable! At that age, I did not know the language of engineering. I only knew that I was looking at something extraordinary and wondering, what could possibly make a material behave like that?
That question stayed with me longer than I realized.
My journey began in mechanical engineering, where I learned how machines move, how structures carry loads, how parts are designed, and how they fail. I loved the logic of it. I loved understanding how forces travel through a component and why a design works or breaks.
But slowly, my attention kept moving deeper.
Behind every machine, there was a material. Behind every structure, there was a microstructure. Behind every failure, there was a story hidden inside the metal, polymer, ceramic, or composite.
That is when I began to understand that materials are not just the things we make objects from. Materials decide what those objects can become.
A material can make something lighter. Stronger. Safer. More flexible. More resistant to heat. More reliable over time. In many ways, the material is not just part of the design. It is the foundation of the design.
During my early research experiences, I worked with composite materials, and my interest only grew. Composites taught me that materials can be engineered almost like recipes: different ingredients, different arrangements, different properties. A small change in structure can completely change performance.
That idea fascinated me.
It made me see materials as living records of processing, temperature, chemistry, and time. They may look still from the outside, but inside, they carry history. They remember how they were made. They respond to heat. They change under stress. They evolve.
Today, as a master’s student in Materials Engineering at McGill University, I work on aluminium alloys made by metal additive manufacturing, commonly known as metal 3D printing.
In this process, a laser melts thin layers of metal powder, one layer at a time, until a complete part is built. It sounds futuristic, and in many ways it is. But perhaps a more poetic way to describe 3D printing is that it allows us to grow metal.
Unlike traditional manufacturing, where a part is often carved, cut, or machined from a larger block, additive manufacturing builds upward from powder. Layer by layer, the material takes shape, almost like an idea becoming physical. In that sense, 3D printing brings us closer to the way imagination works: we do not imagine by subtracting material away; we imagine by growing forms, possibilities, and futures.
For industries such as aerospace, transportation, and advanced manufacturing, this is exciting. It means lighter parts, more efficient designs, and geometries that would be difficult or even impossible to make using traditional methods.
But the scientist in me is interested in what happens after the part is printed.
Because a printed metal part may look finished from the outside, but inside, its story is still unfolding.
My research focuses on F357, an aluminium-silicon-magnesium alloy produced by laser powder bed fusion. I study how this alloy changes after heat treatment and long-term exposure to elevated temperature.
In simple words, I ask: what happens inside 3D-printed aluminium when it spends a long time in heat?
The answer is hidden in the microstructure.
Under the microscope, aluminium is not just “aluminium.” It is a landscape. There are tiny silicon particles, strengthening precipitates, aluminium cells, interfaces, and fracture features. These details are invisible to the naked eye, but they control how the material behaves.
A small silicon particle can influence how a crack forms. A tiny precipitate can help strengthen the alloy. A change in particle size can affect whether the material becomes stronger, softer, more brittle, or more ductile.
This is what I find beautiful about materials science, the smallest features can decide the biggest outcomes.
In my work, I study how heat changes these microscopic features over time. During long thermal exposure, particles inside the aluminium can grow, change shape, or lose some of their strengthening effect. As a result, the material’s properties also change.
It may become softer.
It may lose strength.
It may become more ductile.
It may fracture differently.
To most people, these changes may sound small. But for an engineer, they matter. One example that stayed with me is Aloha Airlines Flight 243. In 1988, part of the upper fuselage of a Boeing 737 tore away during flight after years of service. The aircraft still managed to land, but the incident became a major reminder of how fatigue damage, aging, and undetected material degradation can threaten safety. The lesson was clear: a structure does not only need to be strong when it is new. It must remain reliable after thousands of hours of use, repeated loading, temperature changes, vibration, and time.
That is why understanding materials at the microscopic scale matters. A particle, a crack, a weakened interface, or a change in microstructure may seem invisible at first, but in a critical component, what begins inside the material can eventually decide the safety of the entire structure.
This is especially important because 3D-printed metals are not just conventional metals made into complex shapes. The printing process creates a new internal arrangement of phases, particles, and interfaces that is different from traditionally manufactured alloys.
The key question is how this unique microstructure behaves with time: immediately after printing, after heat treatment, and after short-, medium-, or long-term service. Understanding this evolution is essential if we want printed aluminium parts to be not only innovative, but reliable.
Materials Science, in this sense, is not only about discovering something new. It is about learning how to see what was already there.
Looking back, I think I understand why Iron Man’s suit captured my imagination. It represented everything I still find exciting today: strength, lightness, protection, performance, and the possibility of designing materials for extreme demands.
Pour contacter Gargee Dash
To contact Gargee Dash
