The Process-Structure-Property Relationships of a Laser Engineered Net Shaping (LENS) Titanium-Aluminum-Vanadium Alloy that is Functionally Graded with Boron

In this study, we quantified the Chemistry-Process-Structure-Property (CPSP) relations of a Ti-6Al-4V/TiB functionally graded material to assess its ability to withstand large deformations in a high throughput manner. The functionally graded Ti-6Al-4V/TiB alloy was created by using a Laser Engineered Net Shaping (LENS) process. A complex thermal history arose during the LENS process and thus induced a multiscale hierarchy of structures that in turn affected the mechanical properties. Here, we quantified the functionally graded chemical composition; functionally graded TiB particle size, number density, nearest neighbor distance, and particle fraction; grain size gradient; porosity gradient. In concert with these multiscale structures, we quantified the associated functionally graded elastic moduli and overall stress-strain behavior of eight materials with differing amounts of titanium, vanadium, aluminum, and boron with just one experiment under compression using digital image correlation techniques. We then corroborated our experimental stress behavior with independent hardening experiments. This paper joins not only the Process-Structure-Property (PSP) relations, but couples the different chemistries in an efficient manner to effectively create the CPSP relationships for analyzing titanium, aluminum, vanadium, and boron together. Since this methodology admits the CPSP coupling, the development of new alloys can be solved by using an inverse method. Finally, this experimental data now lays down the gauntlet for modeling the sequential CPSP relationships

The Woodpecker\u27s Beak: An Optimally Designed Structure/Material for Energy Absorption and Shock Mitigation

Woodpecker beaks have the ability to absorb shock energy without any damage to their body. In his book Origin of the Species Charles Darwin mentioned that the “woodpecker, with its feet, tail, beak, and tongue, so admirably adapted to catch insects under the bark of trees” in trying to explain how adaptation led to evolutionary changes in the woodpecker. Did the woodpecker with its beak, tongue, tail, and feet really adapt over long periods of evolutionary time or was it designed by its Creator to live in its particular environment and conditions. The analysis in this study shows the intense complexity of the woodpecker’s beak arguing for an engineering design by its Creator. In particular, this study focuses on the structure-property relationships of the woodpecker beak at multiple length scales. In particular, the woodpeckers’ beaks were examined through microscopy and nano/micro indentation to quantify the structure-property relationships with the perspective of mitigating shock waves. The beak of a woodpecker comprises three layers; exterior keratin layer (rhamphotheca) composed of overlapping scales, middle foam layer, and inner bony layer composed of mineral and collagen fiber. Indentation testing revealed that the hardness value of the inner layer is two to three times higher than that of the exterior layer. The overall design of the beak, tongue, and hyoid bone with their specific structure-property relationships in addition to the subsystem designed for shock mitigation appears to have been specifically designed for absorbing energy as they effectively dissipate energy as a whole. The perfection of the beak’s architectural complexity and fine systemization are highly indicative of it being designed by its Creator

Finite Element Analysis of Large Body Deformation Induced by a Catastrophic Near Impact Event

Finite element simulations of near impacts of terrestrial bodies are presented to investigate possible deformation behavior induced by a massive body during the creation week and/or Genesis Flood. Using the universal law of gravitation, a gravitationally loaded objected is subjected to the ‘pull’ of a near passing fly-by object, and the resulting surface deformations are studied. An Internal State Variable (ISV) pressure dependent plasticity model for silicate rocks (Cho et al., 2018) is used to model the deformation behavior and to capture the history effects involved during the complex surface loading/unloading found in a near impact event. The model is used to simulate the earth and a “fly-by” object interaction and is able to accurately reproduce the internal pressure profiles of the earth and fly-by object. In this context, the fly-by object can be the original Moon, a meteor, or another type of large object that has moved through space to interact with the Earth. Due to the wide range of features that can drive surface deformations during a near impact event, a Design Of Experiments (DOE) methodology was used to independently investigate the influences of five parameters (stationary body size, core material, core/mantle thickness ratio, passing object mass, and passing object distance) concerning surface deformation. The results indicate that the passing body distance, stationary body size, and core/mantle ratio are the most dominant influence parameters on surface deformation. Examination of the ISV parameters of the mantle during deformation shows a complex relationship between the hardening and recovery terms of the model and the resulting plastic strain and surface deformation induced from the near pass event. Surface rise from the near passage of a Moon sized object could be as high as 800 m, in turn causing large tsunamis and possibly causing the Earth’s crust to crack. For this first of its kind study, the conclusions provide understanding of the possible ranges of deformations observed from a near pass event and provides insights into possible catastrophic deformation mechanisms relevant to the young Earth paradigm

Elastic Angular Differential Cross Sections for Quasi-One-Electron Collision Systems at Intermediate Energies: (Na⁺, Li⁺)+H and (Mg⁺, Be⁺)+He

Measurements of elastic angular differential cross sections have been carried out for four quasi-one-electron collision systems at intermediate energies. Data are presented for Na++H collisions at laboratory energies of 35.94, 51.75, 63.89, and 143.75 keV, for Li++H collisions at energies of 19.44 and 43.75 keV, for Mg++He collisions at energies of 30, 66.7, and 150 keV, and for Be++He collisions at an energy of 56.25 keV. The highest energy in each case corresponds to a projectile velocity of (1/2 a.u. Born and Eikonal calculations, in which we model the projectile ion as a heavy structureless ion of charge +1e, are also presented. Our model calculations are in fair agreement with the experimental data over the range of measured scattering angles

Angular-Differential Studies of Excitation in Quasi-One-Electron Collisions at High Energy

Qualitative differences have been observed between two types of quasi-one-electron collision systems. We have studied valence-electron excitation at high energy (relative collision velocities up to 0.5 a.u.) in the Mg++He and Na++H collision systems, and find that while Mg++He collisions are dominated by direct excitation, the Na++H collisions exhibit significant molecular excitation, even at the highest velocities. This behavior can be understood in terms of the molecular structure of the respective collision complexes, and the energy separation between the ground and first excited states of the valence electron

Isotope Effect and Momentum-Transfer Scaling in the Elastic-Scattering Differential Cross Sections for Hydrogen-Isotope Collision Systems

A projectile-dependent isotope effect was found for the elastic-scattering differential cross sections in the hydrogen-isotope collision systems. All four differential cross sections lie on a common curve if they are divided by the square of the reduced mass and plotted against momentum transfer. The experimental results are in satisfactory agreement with a simple Glauber-approximation calculation

Angular-Differential Cross Sections for H(2p) Formation in Intermediate-Energy Proton-Helium Collisions

Angular-differential cross sections for charge transfer with simultaneous emission of a photon in collisions of protons with helium atoms have been measured. The incident proton energies were 25, 50, and 100 keV and the center-of-mass scattering angles were between 0 and 2.0 mrad. In the experiment, hydrogen atoms that scattered through an angle θ were detected in coincidence with photons emitted perpendicular to the scattering plane with a wavelength between 1140 and 1400 Å. Differential cross sections for capture into the 2p state of the hydrogen atom were determined from the variation in the coincidence signal with θ. The experimental results are compared with the results of a classical trajectory Monte Carlo (CTMC) simulation and with the results of a calculation for H(2p) capture using the Coulomb-Brinkman-Kramers (CBK) approximation. The agreement between the experimental results and the CTMC calculation is good at all three energies while the agreement between the shape of the data and the CBK calculation is good at 50 and 100 keV

Elastic Differential Cross Sections for Small-Angle Scattering of 25-, 40-, and 60-keV Protons by Atomic Hydrogen

Elastic angular differential cross sections for small-angle scattering of protons by atomic hydrogen have been measured. The technique utilized unambigously distinguishes the elastically and inelastically scattered ions. The cross sections fall monotonically by 3 orders of magnitude in the angular range from 0.5 to 3.0 mrad, in the center-of-mass system. The experimental data obtained are in very good agreement with a multistate calculation and in fair agreement with both our Glauber-approximation and classical-trajectory Monte Carlo results

Angular Differential and Total Cross Sections for the Excitation of Atomic Hydrogen to Its n=2 Level by 25-150-kev Hydrogen Molecular Ions

Experimentally and theoretically determined differential and total cross sections are reported for excitation of atomic hydrogen to its n=2 level by 25-150-keV hydrogen molecular ions. The differential cross sections decrease 3-4 orders of magnitude over the measured center-of-mass scattering-angular range from 0 to 4.5 mrad. The results of a first Born approximation and two other theoretical calculations based upon the Glauber approximation are presented and compared with the experimental results. Both calculations based on the Glauber approximation agree fairly well with the experimental results. The Born approximation agrees moderately well with the experimental results at the very small scattering angles but is well below the experimental results at the larger scattering angles. None of the theoretical calculations presented agree well with the total cross section. However, the results for the total cross section of the two calculations based on the Glauber approximation agree with the experimental results in curve shape better than the Born-approximation results

Measurements of Helium Excitation in Be⁺-He and Mg,⁺-He Collisions

We have observed level specific excitation of He(n = 2, 3) in collisions of Be+ and Mg+ with He at projectile velocities of 1 2 a.u. With both Be+ and Mg+ projectiles, excitation for small scattering angles (large impact parameters) is appreciable, indicating the occurrence of direct excitation. Angular differential excitation cross sections were measured with Mg+ projectiles at c.m. angles up to 9.6 mrad (11.7 keV deg). Molecular excitation begins to dominate these cross sections at about 1.8 keV deg or b ≈ 1.5 a.u.. The total He(n = 2) excitation cross section is (6.86±0.38) x 10-18 cm2 at this velocity, as compared with a Mg+ (3s → 3p) cross section of (8.49±2.09) x 10-17 cm2