Metal 3D Printed Parts Can Be Both Strong and Ductile, According to New Collaborative Research

Share this Article

Plenty of 3D printing research has been completed over the years on metal materials, which are decidedly strong. One adjective we also hear when describing metal 3D printing materials is ductile, meaning the ability to deform under tensile stress. Usually we talk about metal as being either one or the other, but typically not both, and certainly not in terms of 3D printing. But thanks to a team of researchers from Stockholm University in Sweden, the University of Birmingham in the UK, and China’s Zhejiang University, a new metal 3D printing technique can be used to manufacture metals that have both excellent ductility and strength, compared to metal parts made using more traditional manufacturing methods.

“Strength and ductility are natural enemies of one another, most methods developed to strengthen metals consequently reduce ductility,” explained Dr. Leifeng Liu, the project head and an AMCASH research fellow at the University of Birmingham. “The 3D printing technique is known to produce objects with previously inaccessible shapes, and our work shows that it also provides the possibility to produce the next generation of structural alloys with significant improvements in both strength and ductility.”

The joint research team recently published the findings on their new SLM method, which involves a popular stainless steel, in a paper, titled “Dislocation network in additive manufactured steel breaks strength-ductility trade-off,” in the Materials Today journal; co-authors include Dr. Liu, Qingqing Ding, Yuan Zhong, Ji Zou, Jing Wu, Yu-Lung Chiu, Jixue Li, Ze Zhang, Qian Yu, and Zhijian Shen.

According to the paper’s abstract, “Most mechanisms used for strengthening crystalline materials, e.g. introducing crystalline interfaces, lead to the reduction of ductility. An additive manufacturing process – selective laser melting breaks this trade-off by introducing dislocation network, which produces a stainless steel with both significantly enhanced strength and ductility. Systematic electron microscopy characterization reveals that the pre-existing dislocation network, which maintains its configuration during the entire plastic deformation, is an ideal ‘modulator’ that is able to slow down but not entirely block the dislocation motion. It also promotes the formation of a high density of nano-twins during plastic deformation. This finding paves the way for developing high performance metals by tailoring the microstructure through additive manufacturing processes.”

The researchers were able to optimize the process parameters during 3D printing to achieve their results, which could help accelerate the technology toward manufacturing strong and ductile heavy-duty parts.

“This work gives researchers a brand new tool to design new alloy systems with ultra-mechanical properties,” said Dr. Liu. “It also helps metal 3D printing to gain access into the field where high mechanical properties are required like structural parts in aerospace and automotive industry.”

3D printed part for nuclear fusion test reactor. [Image: Dr. Leifeng Liu, University of Birmingham]

The research team’s ultrafast cooling rate, which ranges from about 1,000°C to 100,000,000°C per second, is why their new method of 3D printing strong, ductile materials works. Until the advent of 3D printing technology, this high level of cooling was not possible to achieve in bulk metal production processes. When metal materials are cooled down that rapidly, they end up in what’s known as a non-equilibrium state, which makes it possible to produce unique microstructures, such as the sub-micro dislocation network. According to the research paper, this network is the main factor behind these improved mechanical qualities.

Dr. Chiu, who is in charge of the Centre for Electron Microscopy at the University of Birmingham’s School of Metallurgy and Materials, set up a micro and nano material testing system inside the university’s electron microscopes. This system, which allows users to analyze a metal sample’s mechanism and performance in-situ during mechanical tests, helps identify effective microstructural features for better properties, as well as help researchers better understand the mechanisms.

As metal 3D printing continues to quickly progress toward widespread industrial application, metal 3D printed products have come under intense scrutiny and skepticism. The technology is not affordable to all, and metal powder 3D printing can cause defects, which deteriorate a product’s mechanical properties. Because the industry’s annual global revenue is estimated to hit over $20 billion by 2025, these types of research projects into the qualities of 3D printing materials are increasingly important.

Discuss this story, and other 3D printing topics, at 3DPrintBoard.com or share your thoughts in the Facebook comments below.

[Source: EurekAlert]

 

Facebook Comments

Share this Article


Related Articles

Patented Metals with Extremely High Carbide Content

University of Pittsburgh Develops Depowdering Machine for Metal Printing



Categories

3D Design

3D Printed Architecture

3D Printed Art

3D printed chicken


You May Also Like

3D Printed Rocket Company Relativity Signs Agreement with Satellite Rideshare Provider Spaceflight

Venture-backed Relativity has been busily disrupting the aerospace industry for the last four years with its 3D printed rockets. Based in Los Angeles, the autonomous rocket factory and launch services leader...

Switzerland: Exciting New Technology Multi-Metal Electrohydrodynamic Redox 3D Printing

Researchers from Switzerland explain more about how metals dissolved and re-deposited in liquid solvents can further AM processes by promoting fabrication without post-processing. Their findings are outlined in the recently...

Processing Parameters in SLM 3D Printing: UK Researchers Test Ti6Al4V Cellular Structures

In ‘The influence of processing parameters on strut diameter and internal porosity in Ti6Al4V cellular structure,’ UK researchers from the University of Birmingham look further into strut size and porosity...

China: Complex GelMA-based Scaffolds Improved with the Addition of Nanoclay

Chinese scientists are delving further into successful bioprinting in ‘3D printing of complex GelMA-based scaffolds with nanoclay,’ exploring why photo-crosslinkable gelatin methacrylate (GelMA) has become so enticing for researchers attempting...


Training


Shop

View our broad assortment of in house and third party products.

Subscribe To Our Newsletter

Subscribe To Our Newsletter

Join our mailing list to receive the latest news and updates from our 3DPrint.com.

You have Successfully Subscribed!