Elasticity in Nickel, Term Paper Example

In the article ‘L.Wang, P.Liu, P.Guan, et al., In situ atomic-scale observation of continuous and reversible lattice deformation beyond the elastic limit, Nature Communications, vol. 4, article No. 2413 (10 Sept. 2013)’, the authors explore the way in which a gradual and continuous lattice deformation occur in bending wires. The authors used nickel nanowires to show the reversible strain, which is extremely elastic compared to other metals. The percentage is over 34% in terms of loading. The experiment was intended in portraying the gradual deformation on lattice. This form of mechanism deformation was noted on the scale of atomic in situ nanowire experiment of bending in an electron microscope. From the experiment, it is notable that the continuous straining in the formation of crystals on lattice is evident.

Following the reading of the article, the subject under scrutiny is the continuous and reversible deformation of lattice beyond the elastic limit. As seen, the theoretical limit of elasticity that makes the crystal to become scientifically unstable is the extreme bound of the achievable stability and elastic material straining. From my understanding, the maximum strain of elasticity that lattice can achieve is not more than 0.2%. This depends on the onset of inelasticity yielding caused by discrete activities dislocation such as stress-induced phase of transformations, and deformation twinning among others. Notably, it is evident that, through the reduction of dimensions of materials to micrometer regime, one can observe large reversible strains of lattice, which range from 2-8%. This exclusively notable on nanowires and micro-pillars, which are arguably some of the materials one can consider to use in conducting such experiments.  In the event inelastic activities closely connected to cracking, twinning and dislocations and transitions of first phase order can be suppressed largely under confining conditions of loading in small regions, it is possible to achieve a reversible strain of lattice above 8%.

In terms of object, the strain of lattice is an obvious interest in material physics and sciences. This object has been the focus of theorists since 1920, with an intention of computing it from the atomistic models. Initially, this object was deemed to have an upper limit of deformation of lattice in metals up to 30%. Owing to this experiment, reports that have been made reveal situ bending in experiments of nickel (Ni), within a transmission of an electron microscope. The experimental evidence shows this object have a continued shear strain of lattice, which is almost 35%. Notably, this can be sustained in a crystalline lattice. Following the release of the stored ultra-large elasticity energy, the highly strained lattices are likely to reverse to their original form. In the bending experiment in situ, the nickel serves as a perfect prove of this. For some objects such as coarse-grained materials, one can see that, yielding takes place at an extremely low strain of 0.2%. Even so, in the case of nano-grained metals, continuous elastic deformation of lattice straining may reach 1%.

From the two readings, several conclusions can be derived, from the lattice straining experiments. In both cases, where coarse grained materials and nano-grained metals are used, the strains of lattice are extremely low. This is mainly being caused by the dislocation activations, and twins of deformation cause by levels of low stress. Probably, the elastic strain can reach up to 8%, when one uses nickel and whisker. Even so, the uniaxial conditions of loading, and continuous strain of lattice cannot be realized. In the observation, the 34.6% record is extremely large than the ideal limits of elasticity in normal situations. This is especially the case because; all the events of inelasticity have been suppressed completely by size and confinement effect. Several reasons are associated with the extreme straining capability depicted in bending nickel. The extreme twinning in the ultra-thin twin lamellae is extremely difficult. Lastly, the bent platelets twins are confined by elastic conditions with a large stress gradient.

I find some sentiments very interesting from the nickel bending experiments and observations. The use of atomic-scale in experiments of situ in depicting the nickel bending, a shear strain on lattice can reach up to 34.6% (Wang, Pan and  Pengfei et al. 6). Arguably, it is interesting to find out that, it has never been possible to prove continuous lattice shear evolution using an experiment. The interventions caused by dislocations have always made this impossible. Interestingly, nickel is the only metal that can store such a high density of elastic energy.

In conclusion, it is evident via the experiments on elasticity that nickel is the only metal that can store such a high density of elastic energy. The properties of these composite materials vary on the basis of the compounds used in the manufacture as well as the technique used in the manufacturing process. It is pertinent to note that the natural polymers available in the universe require reinforcement to ensure the sustainability of the human activities taking place across the world. Advanced fiber reinforced composites are applicable in areas where there is a need for high strength, good mechanical and thermal performance of the material.

Works Cited

Wang, Lihua, Pan, Liu, and  Pengfei, Guan, Pengfei et al., In situ atomic-scale observation of continuous and reversible lattice deformation beyond the elastic limit, Nature Communications, vol. 4, article No. 2413 (10 Sept. 2013). Print