3D Printing

Carbon nanofibers boost the hardness of 3D-printed aluminum

Carbon nanofibers boost the ha...
An aluminum component, 3D-printed using the carbon nanofibers
An aluminum component, 3D-printed using the carbon nanofibers
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An aluminum component, 3D-printed using the carbon nanofibers
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An aluminum component, 3D-printed using the carbon nanofibers

While 3D-printed aluminum parts are becoming increasingly common in the aerospace industry, any weaknesses in those parts can cause them to fail catastrophically. A new additive could help, by making the aluminum 1.5 times harder.

Developed by scientists at Russia's NUST MISIS university, the additive is made up of tiny carbon nanofibers. These are produced as a byproduct of the processing of natural gas, and would ordinarily end up being disposed of – potentially becoming a form of pollution.

Instead, they're added to powdered aluminum. In an existing process known as selective laser melting, a laser beam is used to melt that powder in a specific pattern, building objects up one layer of melted (and subsequently fused) aluminum at a time.

Ordinarily, temperature differences between those layers may cause the microstructure of the finished product to be inconsistent, with some layers ending up more porous than others. Because the carbon nanofibers are very thermally conductive, however, they're reportedly able to distribute the laser heat more thoroughly and evenly.

As a result, the 3D-printed aluminum has a uniform low porosity, and is thus a claimed 1.5 times harder than aluminum printed from powder without the added nanofibers.

The research is being conducted in partnership with the Boreskov Institute of Catalysis, and is described in a paper that was recently published in the journal Composites Communications.

Source: NUST MISIS

4 comments
paul314
For some parts you want hardness, but if you're worried about catastrophic failure, toughness and yield strength are what you want. In metals, hard often translates to brittle, which is the opposite of what you want.
Bob Stuart
I'm with Paul. Hardness is tested with an impact to make a dent, so at least the stuff is not catastrophically brittle, but that term does not really describe a metal. What effect do the inclusions have on strength, stiffness, and elongation? What is the percentage?
Pancho Molina
The carbon in contact with the aluminum will create a Volta effect because something will be hygroscopic oxidizing the aluminum , they don't said anything about this kind of reaction between dissimilar materials.
Kpar
Paul is right on the money about hardness vs toughness.

My question is, must this process be done in an oxygen free environment? Seems to be lasing the nanofibers would likely cause them to burn in the process.