IISc low-cost technique to produce metal powders for 3D printing | India News

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BENGALURU: A team of researchers from the Indian Institute of Science (IISc), addressing current techniques for obtaining metal powder, a major source of additive manufacturing (AM) – also known as 3D printing – has identified an alternative low cost technique for producing metal powders.
Highlighting how AM or 3D printing creates objects by adding material, layer by layer, an IISc statement states that metal powders are primarily produced using a technique called atomization, in which a stream of molten metal is split into fine droplets using air or water. jets.
“However, despite its widespread use, atomization yields poor performance, is expensive, and lacks flexibility in the types of materials it can process. A team led by Koushik Viswanathan, Assistant Professor, Department of Mechanical Engineering (DME) , has identified an alternative technique that circumvents these issues. This has exciting implications for AM processes in general, including areas such as the fabrication of biomedical implants,” the release reads.
In the metal grinding industry, the removed material – called shavings – is often discarded as waste, the IISc said, adding that it is usually stringy in shape, like metal shavings, but emits often also perfectly spherical particles.
While scientists have long theorized that these bodies go through a process of melting to take on the spherical shape, thus posing interesting questions like whether the heat of grinding causes the melting or is there any melting at all, the Viswanathan’s team showed that these powdery metallic bodies form as a result of melting due to the high heat of oxidation, an exothermic reaction, at the surface layer.
IISc said the team then refined this process to produce large quantities of spherical powders, which are collected and further processed for use as source material in AM. Their study shows that these particles perform as well as commercial gas-atomized powders in the context of metallic AM.
Priti Ranjan Panda, PhD student at IISc’s Product Design and Manufacturing Center and one of the study’s authors, said: “We have an alternative, more cost-effective and inherently scalable way to manufacture metal powders, and the quality of the final powders seem to be very competitive compared to conventional gas atomized powders.
Elaborating on the applications of their findings, Viswanathan said there has recently been significant interest in the adoption of metallic AM because, by its nature, it allows for significant customization and enables design freedom.
“However, the high cost of metal powders in stock has been the stumbling block. We hope our work will open new doors to making metal powders cheaper and more accessible,” he said.
Reducing the cost of the AM process may expand the range of materials in situations such as the fabrication of biomedical implants, which could become cheaper and more accessible, said Harish Singh Dhami, a doctoral student at DME and co-author of the study.
He added that metal powder fabrication by abrasion also has potential in other high-performance applications such as aircraft engines, where a high degree of specificity and sophistication is required.
Additionally, metal powders produced in an atomization facility require transportation for casting and recycling, creating a large supply chain.
“It works for abundant metals like aluminum, but for strategic materials like tantalum and lithium, where the extraction alone is a complex process, it would be beneficial to have a scalable process to produce metal powders. Then, in principle, the whole supply chain can be housed in one facility – a possibility their technique could provide,” Vishwanath added.
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