Materials Discovery最新文献

A low artificial anisotropy cellular automaton (CA) model is developed for the simulation of microstructure evolution in directional solidification. The CA model’s capture rule was modified by a limited neighbor solid fraction (LNSF) method. Various interface curvature calculation methods have been compared. A modified curvature calculation method based on the variation of the unit vector normal (VUVN) to the solid-liquid interface using volume of fluid (VOF) interpolation technique gets better results. The equilibrium shapes were simulated to quantify the artificial anisotropy, when the interface energy anisotropy coefficient is varied from ε = 0.0 to ε = 0.05. The low artificial anisotropy CA model is used in the numerical simulation of the cell-to-dendrite transition (CDT) in directional solidification. The influence of physical parameters (Г, D_l, k₀, m_l) on CDT has been investigated. The main finding in this paper is the discovery of the changing behavior of the V_cd when the solute partition coefficient k₀ is larger than a critical value. When k₀ is less than 0.125, the V_cd follows the Kurz and Fisher criterion V_c/k₀; while when k₀ > 0.125, the V_cd equals to 8 V_c. The experimental data of succinonitrile-acetone (SCN-ace, k₀ = 0.1) and SCN-camphor (k₀ = 0.33) support the conclusions from CA simulations.

Nanocrystalline GdAlO₃ with particle size of 40 nm has been studied in form of tablets by means of dielectric spectroscopy. Impedance, phase angle, capacitance, relative dielectric permittivity, and loss tangent have been measured in the frequency range 20 Hz–1 MHz at temperatures between 298 K and 473 K. The polarizability volume of GdAlO₃ has been determined and the dielectric properties of the material have been discussed.

The industrial and research sectors make significant investments in developing and producing engineering materials. These materials are manufactured and qualified in accordance with a body of product and testing standards that have evolved over many decades to meet ever more demanding requirements. Yet the very significant volume of data that result from these activities remains largely unavailable. While efforts to establish a digital infrastructure for engineering materials data can be traced back more than three decades, widespread adoption of machine-readable formats to enable the routine transfer of engineering materials data has yet to be realized. Given the reliance on electronic systems in all aspects of engineering materials development, manufacture, and qualification, it is an anomaly that simply preserving and transferring engineering materials data remains an issue. This anomaly is accentuated by the fact that in recent years other business domains have benefited from the integration of web technologies into established business models. To address these shortcomings a digital infrastructure is needed that allows and encourages the seamless transfer of engineering materials data between different systems. It is in this context that renewed efforts to develop standard formats for engineering materials data are taking place in the frame of CEN Workshops. While building on prior activities at ASTM and ISO, this work leverages existing product and testing standards with a view to engaging the engineering materials community. With preliminary technical specifications having already been demonstrated to streamline the data transfer process, attention is turning to the long-standing challenge of promoting a culture of data sharing. Whereas previously the motivations for researchers and industrial organizations to share data were lacking, the initial impacts of the DataCite framework for data citation on the utilization of the European Commission materials database hosted at https://odin.jrc.ec.europa.eu are suggestive of a sea-change in data sharing and reuse. This paper describes the status of the work to develop data formats for engineering materials in the frame of CEN Workshops and reports on the added value of data citation beyond simply ensuring that data creators are properly accredited for their work. It also reports the outcome of work to enable the European Commission materials database to support standards compliant data formats and data citation, whereby the barriers to systems integration have been considerably reduced and, irrespective of the level of confidentiality, organizations in both the industrial and research sectors now routinely enable their data sets for citation. Together with recent innovations in digital publishing, a renewed interest in the development of standards for engineering materials data offers new prospects for discovery, exchange, and reuse of engineering mate