Comparison of Optical and Stylus Methods for Surface Texture Characterisation in Industrial Quality Assurance of Post-Processed Laser Metal Additive Ti-6Al-4V.

Additive manufacturing technologies enable lightweight, functionally integrated designs and development of biomimetic structures. They contribute to the reduction in material waste and decrease in overall process duration. A major challenge for the qualification for aerospace applications is the surface quality.

Influence of Contour Scan Variation on Surface, Bulk and Mechanical Properties of LPBF-Processed AlSi7Mg0.6.

Metal additive manufacturing technologies have great potential for future use in load-bearing aerospace applications, requiring a deeper understanding of mechanical performance and influencing factors. The objective of this study was to investigate the influence of contour scan variation on surface quality, tensile and fatigue strength for laser powder bed fusion samples made of AlSi7Mg0.6 material and to create high-quality as-built surfaces.

Predicting water sorption and volume swelling in dense polymer systems via computer simulation.

Atomistic model structures of amorphous polyamide 6 (PA-6) and of an adhesive system consisting of the diglycidyl ether of bisphenol A (DGEBA) as epoxy resin and isophorone diamine (IPD) as a curing agent are generated. For the adhesive, we use a new approach for the generation of the cross-linked polymer networks. It takes into account the chemical reaction kinetics of the curing reaction and, therefore, results in more realistic network structures.

Determining the structure of α-phenylethyl isocyanide in chloroform by VCD spectroscopy and DFT calculations--simple case or challenge?

The present work provides a comprehensive theoretical and experimental study of the vibrational circular dichroism of (S)-α-phenylethyl isocyanide in chloroform. The structure in solution is investigated systematically by density functional theory calculations starting from the isolated molecule and then by considering solvent effects implicitly using the PCM and explicitly by taking into account molecular complexes of the isocyanide molecule and chloroform. Furthermore, the influence of dimerisation is evaluated, and it is finally found that the structure of (S)-α-phenylethyl isocyanide in chloroform is best described assuming a solvated dimer.

VCD study of alpha-methylbenzyl amine derivatives: detection of the unchanged chiral motif.

Chiral alpha-methylbenzyl amine is a well known and often used chiral auxiliary, e.g., in the resolution of racemates or asymmetric catalysis.

Computational studies on polymer adhesion at the surface of gamma-Al2O3. I. The adsorption of adhesive component molecules from the gas phase.

We calculate the minimum energy paths and reaction energies of the adsorption of the epoxide adhesive components diglycidylesterbisphenol A (DGEBA), diethyltriamine (DETA), and the adhesion promoter 3-aminopropylmethoxysilane (AMEO) at two different sites on a model of the native Al2O3 surface, using the nudged elastic band algorithm in conjunction with self-consistent charge-density functional based tight binding. Our results show that the chosen combination of methods is well suited to obtain an overview of the reaction mechanisms and kinetics of the adsorption of organic molecules on inorganic surfaces. The obtained MEP-s show that there is preference for the adsorption of the adhesion promoter, AMEO, over the resin, DGEBA, while the adsorption of the curing agent, DETA, is unfavorable.

Theoretical study of the interaction between selected adhesives and oxide surfaces.

We investigate the competition of the various organic components of two representative adhesive systems for reactive defect sites at model surfaces of both SiO2 and Al2O3. The reaction energies of resin monomers, curing agents, and in some cases also of additional adhesion promoters with the defects are calculated. We applied a density-functional based tight-binding method including a self-consistent correction of the Mulliken charges, which has already proven to be a useful tool for computational materials science, delivering reliable structural and energetic information.