image: The 3D printer used in the study. view more
Credit: Oleg Dubinin et al./The Journal of Materials Processing Technology
Scientists from Skoltech and their colleagues have used a 3D printer to fuse two materials in an alloy whose composition continuously changes from one region of the sample to the other, endowing the alloy with gradient magnetic properties. Despite the nonmagnetic nature of the constituent materials, the alloy exhibits magnetic properties. Published in The Journal of Materials Processing Technology, the study also offers a theoretical explanation for the phenomenon.
Once perceived as a mere novelty tool for rapid prototyping, 3D printing has grown into a full-blown industrial technology used to produce airplane parts, patient-matched implants and prosthetics, jewelry, and custom-fit shoes, among other things.
The main advantage of 3D printing is the ability to produce objects with very complex shapes that are impossible or too expensive to make with conventional manufacturing techniques, such as casting, rolling, and stamping. The technology also enables faster and riskier prototyping, and greater flexibility in terms of product customization and how many items are produced. And then there’s the added benefit of reduced waste.
One of the limitations of 3D printing is that it tends to use one homogeneous material or mixture throughout the entire item produced. By varying the composition from one part of the item to another, it could be endowed with properties that continuously change.
An example of this would be a rod made of an alloy of two metals whose ratio changes from 100% metal A to fifty-fifty, to 100% metal B, and so on. Provided that the metals in question mix well, without giving rise to defects, the rod’s gradient properties — including magnetic ones — could be technologically useful, for example, for motor rotors, strips for magnetic encoders, or transformators.
The authors of a recent Skoltech-led study published in The Journal of Materials Processing Technology report an experiment where they produced such an alloy. Its two components — the metals A and B above — are themselves alloys: aluminum bronze (copper, aluminum, and iron) and marine-grade stainless steel (mostly iron, chromium, and nickel). Both are technically known as paramagnetic, or “nonmagnetic” in layman’s terms. That is, they don’t stick to a magnet. Yet when they are mixed in equal proportions, the resulting alloy turns out to be a “soft” ferromagnet. That is, it is attracted to “hard” ferromagnets — like the one on the fridge — but does not itself become one.
“We used these two paramagnetic materials to create a gradient alloy with an InssTek MX-1000 3D printer. It employs a technique called directed energy deposition, which involves depositing powdered material from a nozzle and simultaneously melting it with a laser. The resulting alloy exhibited ferromagnetic properties to an extent that depended on the ratio between the two constituent materials,” said the study’s lead author Oleg Dubinin from the Additive Manufacturing Lab at Skoltech.
“Our study also provides a theoretical explanation of the emergence of ferromagnetic properties in the alloy in terms of its atomic structure,” the researcher went on. “While the two initial materials have a so-called face-centered cubic crystal structure, their combination results in a body-centered cubic structure.”
In the former, metal atoms sit in the corners of imaginary cubes and on their faces. In the latter, there are metal atoms at the centers of the invisible cubes instead of on their faces. This second arrangement gives the material its ferromagnetic properties.
“Gradient soft magnetic alloys could find applications in machine engineering, for example, in electrical motors,” commented PI Stanislav Evlashin, a leading research scientist at Skoltech. “Our findings show that directed energy deposition is not just a way to 3D-print gradient materials, but also a way to discover new alloys. Besides that, the technology is highly efficient and suitable for manufacturing even large-size parts quickly.”
Besides the researchers from Skoltech, the study reported in this story features scientists from St. Petersburg State Marine Technical University, National Research Center Kurchatov Institute, and Belgorod State University.
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Skoltech is a private international university located in Russia. Established in 2011 in collaboration with the Massachusetts Institute of Technology (MIT), Skoltech is cultivating a new generation of leaders in the fields of science, technology, and business, conducting research in breakthrough fields, and promoting technological innovation with the goal of solving critical problems that face Russia and the world. Skoltech is focusing on six priority areas: artificial intelligence and communications, life sciences and health, cutting-edge engineering and advanced materials, energy efficiency and ESG, photonics and quantum technologies, advanced studies. Website: https://www.skoltech.ru/.
Journal
Journal of Materials Processing Technology
Method of Research
Experimental study
Article Title
Gradient soft magnetic materials produced by additive manufacturing from non-magnetic powders
Article Publication Date
9-Oct-2021
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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
