̽��ֱ�� of Cambridge - A* Singapore

Using lasers to ‘heat and beat’ 3D-printed steel could help reduce costs

sc604 — Mon, 30 Oct 2023 09:01:39 +0000

̽��ֱ��method, developed by a research team led by the ̽��ֱ�� of Cambridge, allows structural modifications to be ‘programmed’ into metal alloys during 3D printing, fine-tuning their properties without the ‘heating and beating’ process that’s been in use for thousands of years.

̽��ֱ��new 3D printing method combines the best qualities of both worlds: the complex shapes that 3D printing makes possible, and the ability to engineer the structure and properties of metals that traditional methods allow. ̽��ֱ��results are reported in the journal Nature Communications.

3D printing has several advantages over other manufacturing methods. For example, it’s far easier to produce intricate shapes using 3D printing, and it uses far less material than traditional metal manufacturing methods, making it a more efficient process. However, it also has significant drawbacks.

“There’s a lot of promise around 3D printing, but it’s still not in wide use in industry, mostly because of high production costs,” said Dr Matteo Seita from Cambridge’s Department of Engineering, who led the research. “One of the main drivers of these costs is the amount of tweaking that materials need after production.”

Since the Bronze Age, metal parts have been made through a process of heating and beating. This approach, where the material is hardened with a hammer and softened by fire, allows the maker to form the metal into the desired shape and at the same time impart physical properties such as flexibility or strength.

“ ̽��ֱ��reason why heating and beating is so effective is because it changes the internal structure of the material, allowing control over its properties,” said Seita. “That’s why it’s still in use after thousands of years.”

One of the major downsides of current 3D printing techniques is an inability to control the internal structure in the same way, which is why so much post-production alteration is required. “We’re trying to come up with ways to restore some of that structural engineering capability without the need for heating and beating, which would in turn help reduce costs,” said Seita. “If you can control the properties you want in metals, you can leverage the greener aspects of 3D printing.”

Working with colleagues in Singapore, Switzerland, Finland and Australia, Seita developed a new ‘recipe’ for 3D-printed metal that allows a high degree of control over the internal structure of the material as it is being melted by a laser.

By controlling the way that the material solidifies after melting, and the amount of heat that is generated during the process, the researchers can programme the properties of the end material. Normally, metals are designed to be strong and tough, so that they are safe to use in structural applications. 3D-printed metals are inherently strong, but also brittle.

̽��ֱ��strategy the researchers developed gives full control over both strength and toughness, by triggering a controlled reconfiguration of the microstructure when the 3D-printed metal part is placed in a furnace at relatively low temperature. Their method uses conventional laser-based 3D printing technologies, but with a small tweak to the process.

“We found that the laser can be used as a ‘microscopic hammer’ to harden the metal during 3D printing,” said Seita. “However, melting the metal a second time with the same laser relaxes the metal’s structure, allowing the structural reconfiguration to take place when the part is placed in the furnace.”

Their 3D printed steel, which was designed theoretically and validated experimentally, was made with alternating regions of strong and tough material, making its performance comparable to steel that’s been made through heating and beating.

“We think this method could help reduce the costs of metal 3D printing, which could in turn improve the sustainability of the metal manufacturing industry,” said Seita. “In the near future, we also hope to be able to bypass the low-temperature treatment in the furnace, further reducing the number of steps required before using 3D printed parts in engineering applications.”

̽��ֱ��team included researchers from Nanyang Technological ̽��ֱ��, the Agency for Science, Technology and Research (A*STAR), the Paul Scherrer Institute, VTT Technical Research Centre of Finland, and the Australian Nuclear Science & Technology Organisation. Matteo Seita is a Fellow of St John’s College, Cambridge.

Reference:
Shubo Gao et al. ‘Additive manufacturing of alloys with programmable microstructure and properties.’ Nature Communications (2023). DOI: 10.1038/s41467-023-42326-y

Researchers have developed a new method for 3D printing metal that could help reduce costs and make more efficient use of resources.

This method could help reduce the costs of metal 3D printing, which could in turn improve the sustainability of the metal manufacturing industry

Matteo Seita

Jude E. Fronda

Retrieval of a stainless steel part made by 3D printing

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New research leaves tumours with nowhere to hide

Anonymous — Thu, 24 Sep 2015 09:25:29 +0000

̽��ֱ��small tumours concealed in the adrenal gland are “unmasked” in early pregnancy, when a sudden surge of hormones fires them into life, leading to raised blood pressure and causing risk to patients.

New research published today in the New England Journal of Medicine conducted by a team led by Professor Morris Brown, professor of clinical pharmacology at Cambridge ̽��ֱ�� and a Fellow of Gonville & Caius College, identifies this small group of lurking tumours for the first time, and explains why they behave as they do.

̽��ֱ��study means that, when patients are found to have high blood pressure early in pregnancy, doctors will now be encouraged to consider that the cause could be the tumours, which can be easily treated. Currently, adrenal tumours are not usually suspected as the cause of high blood pressure in pregnancy, and so go undiagnosed.

Brown and an international group of PhD students including first-author Ada Teo of Newnham College used a combination of state-of-the-art gene “fingerprinting” technology and old-fashioned deduction from patient case histories to work out that the otherwise benign tumours harbour genetic mutations that affect cells in the adrenal gland.

̽��ֱ��mutation means the adrenal cells are given false information and their clock is effectively turned back to “childhood”, returning them to their original state as ovary cells. They then respond to hormones released in pregnancy, producing increased levels of the salt-regulating hormone aldosterone.

Aldosterone in turn regulates the kidneys to retain more salt and hence water, pushing up blood pressure. High blood pressure – also known as hypertension – can be fatal, since it greatly increases the risk of stroke and heart attack.

̽��ֱ��new findings build on a growing body of research focusing on the adrenal gland and blood pressure. Sixty years ago, the American endocrinologist Dr Jerome Conn first observed that large benign tumours in the adrenal gland can release aldosterone and increase blood pressure (now known as Conn’s Syndrome).

Brown and his team have previously found a group of much smaller tumours, arising from the outer part of the gland, that have the same effect. ̽��ֱ��latest discovery drills down still further, revealing that roughly one in ten of this group has a mutation that makes the cells receptive to pregnancy hormones.

Brown said: “This is an example of what modern scientific techniques, and collaborations among doctors and scientists, allow you to do [through a form of genetic fingerprinting]. Conditions are often around for 60 years which we have had no explanation for, and now we can get to the heart of what has gone wrong.”

But the discovery also relied on what doctors call “clinical pattern recognition” – using experience to spot similarities. Brown was able to link together the cases of two pregnant women almost ten years apart and a woman in early menopause. All suffered high blood pressure, leading him to screen their adrenal tumours and identify a matching genetic mutation.

Pregnant women found to have the newly identified subset of tumours can now be identified more readily, and the tumours either treated with drugs or potentially even removed.

̽��ֱ��research was funded by the Wellcome Trust, National Institute for Health Research, British Heart Foundation and A* Singapore.

Hidden tumours that cause potentially fatal high blood pressure but lurk undetected in the body until pregnancy have been discovered by a Cambridge medical team.

Conditions are often around for 60 years which we have had no explanation for, now we can get to the heart of what has gone wrong

Morris Brown

11C metomidate PET CT of small Conn's tumour

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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