In the United States might be one step closer to achieving its goal to have half of the new cars sold by 2030 to be electric vehicles that emit no emissions. This is thanks to two MIT students and their graduate student mentor in Germany they developed the first type of steel, not just for car construction and construction but for die-casting molds used to make them into just two or three pieces.
MIT students Ian Chen and Kyle Markland, who graduated in 22nd grade, placed third in the ASM Materials Education Foundation’s Student Design Contest. The 3D-printable steel alloy that won the award was inspired by a novel manufacturing method called Giga-casting. which was popularized by the car maker Tesla and utilized to build the electric Model Y.
Chen also received the award at an event held in New Orleans on September 12. Chen and Markland will each share the prize of $1,000. ASM Materials Education Foundation is the charitable division of the materials engineering group ASM International. Its mission is to encourage STEM-related careers for teachers and students.
A design challenge
Chen and Markland’s work is rooted in a class last spring, 3.041 (Computational Material Design), which Gregory Olson, the Thermo-Calc Professor of Practice at MIT, taught. Olson is among the top researchers worldwide in computational materials science. It employs computers to model and simulate to discover and design new materials. Apple has utilized its approach in developing its Apple Watch and has caught the eye of Tesla President and CEO Elon Musk.
“To get affordable electrical cars with good range, he had to make aluminum structures affordable,” Olson explains. Olson about Musk. “So Musk looked at the type of casting dies for tiny cars and thought, “Why don’t we expand it? We’ll make the whole vehicle.'”
Tesla employed Olson’s algorithm to determine the amount of aluminum that can be cast in die casting — which is the process whereby the molten metal is put into a mold to create objects. Most cars are constructed using hundreds of die-cast components, such as brackets, engine cylinders, and various other parts, assembled in the automated line to create the vehicle. The Giga-casting method named after the vast casting equipment referred to by the name of Giga Press — instead is a matter of casting two or three large car parts, drastically simplifying the process and its cost.
The problem is that “when you scale up the process, the heat transfer is slower, and the cycle times are too long,” Olson states that this liquid metal needs longer to cool, making the entire process less efficient and expensive.
A technique known as ” conformal cooling” can be helpful. It is a method where small channels are shaped to follow the form of the object being cast, and coolant or water is pumped through them to speed up cooling.
This was when the problem took shape. Charles Kuehmann, vice president of materials engineering at SpaceX and Tesla and a former Olson’s student, has identified the need for higher-quality die steel, often known as tool steel, and is “printable” — a material that can be put into a 3-D printer that prints new dies that have greater strength and thermal properties. Conventional steels, Olson said, “are quite brittle and cracking-prone if you try to print them.”
As an advisor to the team of students, Olson turned to Florian Hengsbach. Hengsbach is a student from MIT who is a student at Paderborn University who returned to Germany amid the pandemic shutdowns in 2020.
His doctoral dissertation could not be more appropriate to the MIT project that focuses on tool steel design in additive manufacturing, a term often used in conjunction with 3D printing. He is the supervisor of Mirko Schaper, the dean of Paderborn’s school of mechanical engineering, the head of the department of materials science, and an expert on additive manufacturing.
“Here at Paderborn, we print materials, characterize them down to the atomic level, and determine the process-microstructure-performance correlation,” Hengsbach says — in other words, understand how the material will behave in various 3D printing conditions.
Alongside Hengsbach who was working across Europe in Europe, and Chen and Markland in Cambridge, Massachusetts, the team started to design the new metal by using CALPHAD an approach to measuring the properties of materials. Utilizing thermodynamic models of materials, the team was able to predict how contemporary metals would perform under various conditions.
Hengsbach developed the material at Paderborn’s additive manufacturing center and printed it for an experiment. He made the metal alloy that he had invented by melting it and creating tiny droplets that solidify and form a powder. The powder is then coated and then melted with lasers into an object printed by 3D printing.
“This was very successful,” Hengsbach states. “We’ve designed a very promising tool steel, with superior performance regarding thermal conductivity, hardness, and toughness, which can actually be printed.”
The new metal also has possibilities for manufacturing, Hengsbach explains -injection molding, which is used typically for plastics, or press hardening that can make high-strength stainless steel in intricate shapes, or in other processes -that is – “everywhere you want to use conformal cooling channels, this material can be used.”
Hengsbach returns to MIT on February 23, 2023, and will be an Olson postdoc in the research group.
“You won’t regret it.”
The team has filed the U.S. patent application for the new die steel that can be printed. The next step is to test for casting die applications. Discussions with Tesla are ongoing.
In what could be a possible acknowledgment of the team’s unique metallic material, Musk posted in September. 9, to over 100 million followers. “Take Materials Science 101. You will never regret doing it.”
For Chen, a junior majoring in engineering and materials science, steel design has proven that he would like to remain on a material-related track for his graduate studies.
“This project has pushed me toward a more computationally driven materials area,” Chen states, “where computational models are used as a critical tool for materials design and analysis.”
Markland completed his degree in May with a B.S. in engineering and materials science and recently began working full-time at the Ford Motor Company in Dearborn, Michigan. As part of his Ford College Graduate program, Markland will work on various projects over his first two years, beginning with vehicle paint and corrosion protection engineering.
“It feels great to have our work recognized by ASM,” Markland states. “Sometimes classwork can feel abstract or removed from the real world, and it’s a refreshing reminder that the project we did has recognition beyond just a class assignment.”