Related Experiment Video
Updated: Jan 20, 2026
Processing of Bulk Nanocrystalline Metals at the US Army Research Laboratory
Published on: March 7, 2018
Bulk ultrafine grained/nanocrystalline metals via slow cooling
Chezheng Cao1,2, Gongcheng Yao1,2, Lin Jiang3,4
1Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Nanoparticles enable ultrafine-grained (UFG) metal fabrication via slow cooling, overcoming previous limits. This novel method offers enhanced thermal stability and broad applications in materials science.
Area of Science:
- Materials Science
- Metallurgy
- Nanotechnology
Background:
- Controlling nucleation and phase growth is crucial for refining metal microstructures and enhancing material properties.
- Ultrafine-grained (UFG) and nanocrystalline metals exhibit superior performance but are challenging to produce in bulk.
- Conventional refinement techniques like rapid cooling face fundamental limitations.
Purpose of the Study:
- To introduce a new method for fabricating bulk ultrafine-grained (UFG)/nanocrystalline metals.
- To demonstrate the effectiveness of nanoparticles in controlling grain refinement during slow cooling.
- To investigate the thermal stability of UFG/nanocrystalline metals produced by this method.
Main Methods:
- Utilizing nanoparticles to induce a continuous nucleation and growth control mechanism.
- Applying slow cooling techniques to metal processing.
- Characterizing the resulting microstructures and thermal properties.
Main Results:
- Achieved grain refinement to ultrafine/nanoscale dimensions in bulk metals.
- Demonstrated that nanoparticles facilitate continuous nucleation and growth control during slow cooling.
- Observed unprecedented thermal stability in the nanoparticle-enhanced UFG/nanocrystalline metals.
Conclusions:
- Nanoparticle addition provides a viable pathway to overcome limitations in conventional grain refinement.
- This method enables the production of bulk UFG/nanocrystalline metals with enhanced thermal stability.
- The discovered mechanism has potential for widespread application in various cooling, nucleation, and phase growth processes.
Related Concept Videos
08:58Processing of Bulk Nanocrystalline Metals at the US Army Research Laboratory
06:52Nanocrystalline Alloys and Nano-grain Size Stability
Alloys with grain size less than 100 nm are known as nanocrystaline alloys. Due to their enhanced physical and mechanical properties, there is an ever-increasing demand to employ them in various industries such as semiconductor, biosensors and aerospace.
To improve the processing and application of nanocrystalline alloys, it is necessary to develop close to...
09:13Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction
05:04Determining the Mechanical Strength of Ultra-Fine-Grained Metals
09:18Simple Methods for the Preparation of Non-noble Metal Bulk-electrodes for Electrocatalytic Applications
02:44Heating and Cooling Curves
For instance, the addition of heat raises the temperature of a solid; the amount of heat absorbed depends on the heat capacity of the solid (q = mcsolidΔT). According to thermochemistry, the relation between the amount of heat absorbed or released by a substance, q, and its...