Dear Researchers & Professors,
Please let me know the answers for the following queries.
1. What do we mean by the hardness of a nanoparticle?
2. If the hardness of Al2O3 nanoparticle is 1440 kg/mm2, what does that mean?
3. How could we measure the hardness of the nanoparticle, then?
Thanks for answering.
Article Mechanical properties of nanoparticles: Basics and applications
Go through this paper.
The special mechanical properties of nanoparticles allow for novel applications in many fields, e.g., surface engineering, tribology and nanomanufacturing/nanofabrication.
As such, research topics on the mechanical properties of nanoparticles have become increasingly hot in recent years; the number of relevant publications has increased dramatically, as shown in figure 1. Nanoparticles show different mechanical properties relative to microparticles and bulk materials, providing more effective options for the surface modification of many devices in the mechanical strength, or to improve the quality of nanomanufacturing/nanofabrication, etc. To be more specific, on the one hand, the mechanical effects of nanoparticles can affect the tribological properties of lubricants with nanoparticles [12] as well as reinforce composite coatings [13]. In a lubricated contact, the comparison in the hardness between nanoparticles and the contacting surface determines whether particles are deformed or indented into the surface when the contact pressure is sufficiently large [14]. This information could reveal how the particles behave in the contact. On the other hand, nanoparticles are usually used as abrasives in the nanopolish of ultra-smooth surfaces by chemical mechanical polishing (CMP), which is the most effective planarization tool in the manufacture of an integrated circuit (IC), till now. Good controls over the mechanical properties of particles and their interactions with the polished surface etc are important for improving the surface quality and enhancing material removal [15, 16]. Successful applications in these fields usually need a deep understanding of the basics of the nanoparticles' mechanical properties, such as hardness and elastic modulus, interfacial adhesion and friction, movement law, as well as their size-dependent effects. In order to acquire more of this information, different testing methods have been developed, e.g., nanoindentation with atomic force microscopy (AFM) [17, 18], in situ compression by a force probing holder based on the observation with transmission electron microscopy (TEM) [19,20]. However, the obtained results are still inadequate and some are controversial. For instance, there is still no definite conclusion as to whether the elastic modulus of nanoparticles measured with AFM is affected by the particle size and the indentation depth.
Dear Prof. Jyoti,
I thank you for sharing such a good article and am very clear with the paper.
The questions 1 and 3 are answered through this paper.
Am awaiting for the answer pertaining to Question no.2.
However, am thankful again for providing me a solution at this crucial juncture.
dear Suseel Jai Krishnan; at grain size d < dc a small scale intergranular processes dominated the neighboring atoms grain boundaries, that described by the Hall-Petch law , ∆σg ~ d-1/2, while at d > dc, the dislocations and motion is the dominate activate intergranular processes that depend on the d-1/2 as shown in Figure 1. for more details read;
Article Study the Influence of the Anodizing Process Parameters on t...
Dear Prof. Mahmood,
I wholeheartedly thank you for this source of reply.
But please help me in understanding query 2.
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