Nanoparticles improve the strength of metallic alloys

June 28, 2017, Agency for Science, Technology and Research (A*STAR), Singapore
Nanoparticles improve the strength of metallic alloys
Adding nanoparticles improves the properties of superalloy components created using laser-aided additive manufacturing. Credit: A*STAR Singapore Institute of Manufacturing Technology

Superalloys are the wonder materials of metallurgy. By fine-tuning their composition, scientists can increase mechanical strength and improve resistance to corrosion and high-temperature shape changes. A*STAR researchers have shown that adding nanoparticles can make these materials even stronger.

Inconel 625 is a superalloy that is 55-70 per cent nickel with added chromium, molybdenum, iron, niobium-tantalum, plus trace amounts of numerous other metals. Inconel 625 is used in industrial marine applications because of its high corrosion-fatigue strength, tensile strength and resistance to chloride-ion stress-corrosion cracking.

Guijun Bi and co-workers from A*STAR's Singapore Institute of Manufacturing Technology and Institute of Materials Research and Engineering have reinforced Inconel 625 using titanium diboride nanoparticles. The improved superalloy is fabricated by a sophisticated technique known as laser-aided .

Additive manufacturing is a class of fabrication methods that can create full-scale components by building them up one layer at a time. 3-D printing is one well-known example, but for metals, high-power lasers are typically needed. One such method is laser-aided additive manufacturing, a novel additive which can be utilized for 3-D printing, surface modification and repair. It works by applying a laser beam as heat source, with the additive melted and deposited on to the surface layer by layer.

"We show that adding nanoparticles to the metal base material is an effective way to tailor the material with significantly improved physical, thermal and mechanical properties, as well as excellent performance in terms of wear and corrosion resistance," explains Bi.

Bi and the team mixed and ground together an Inconel 625 alloy powder and a titanium diboride powder with particles approximately 58 nanometers in size. Their additive manufacturing system comprised a powder nozzle on a six-axis robot along with the output from a high-power fiber laser. In this way, they were able to create one-millimeter thick layers of their material on a carbon steel substrate, which they built up into a rectangular block of 120 × 70 × 10 millimeters.

Analysis of their sample indicated that the titanium diboride nanoparticles mainly aggregated at boundaries between crystalline grains of the Inconel 625. Thus, the titanium diboride acted to reinforce the grain boundary. Mechanical testing of the sample demonstrated a significantly increased material strength, relatively high micro-hardness and good abrasive resistance.

"We hope to develop this approach and explore new composite materials reinforced with for additive " says Bi.

Explore further: Selective laser melting additive technology method for material microstructure formation

More information: Baicheng Zhang et al. Microstructure and mechanical properties of Inconel 625/nano-TiB 2 composite fabricated by LAAM, Materials & Design (2016). DOI: 10.1016/j.matdes.2016.08.078

Related Stories

Researchers study ways to make stronger materials in 3-D

September 18, 2013

( —Aided by funding from NASA and using methods similar to 3-D printing, researchers at Missouri University of Science and Technology are running computer simulations of processes that could lead to stronger, more ...

Using machine vision for 3-D printing

June 6, 2017

Researchers from Carnegie Mellon University's College of Engineering have developed machine vision technology that can autonomously identify and sort metal 3-D printing powder types with an accuracy of more than 95 percent—more ...

Recommended for you

Physicists 'flash-freeze' crystal of 150 ions

February 20, 2019

Physicists at the National Institute of Standards and Technology (NIST) have "flash-frozen" a flat crystal of 150 beryllium ions (electrically charged atoms), opening new possibilities for simulating magnetism at the quantum ...

The holy grail of nanowire production

February 20, 2019

Nanowires have the potential to revolutionize the technology around us. Measuring just 5-100 nanometers in diameter (a nanometer is a millionth of a millimeter), these tiny, needle-shaped crystalline structures can alter ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.