A New Strategy for the High-Throughput Characterization of Materials' Mechanical Homogeneity Based on the Effect of Isostatic Pressing on Surface Microstrain.

A new strategy for the high-throughput characterization of the mechanical homogeneity of metallurgical materials is proposed. Based on the principle of hydrostatic transmission and the synergistic analysis of the composition, microstructure, defects, and surface profile of the chosen material, the microstrain characteristics and changes in surface roughness after isostatic pressing were analyzed. After isostatic pressing, two types of microstrains were produced: low microstrain (surface smoothening with decreasing roughness) and large microstrain (surface roughening with increasing roughness). Furthermore, the roughness of the roughened microregions could be further classified based on the strain degree. The phenomenon of weak-interface damage with a large microstrain (plastic deformation, cleavage fracture, and tearing near nonmetallic inclusions) indicated that the surface microstrain analysis could be a new method of high-throughput characterization for microregions with relatively poor micromechanical properties. In general, the effect of isostatic pressing on the surface microstrain of heat-resistant steel provides a promising strategy for achieving high-throughput screening and statistically characterizing microregions with poor micromechanical properties, such as microregions containing microcracks, nonmetallic inclusions, pores, and other surface defects.

The Tuning of Optical Properties of Nanoscale MOFs-Based Thin Film through Post-Modification.

Optical properties, which determine the application of optical devices in different fields, are the most significant properties of optical thin films. In recent years, Metal-organic framework (MOF)-based optical thin films have attracted increasing attention because of their novel optical properties and important potential applications in optical and photoelectric devices, especially optical thin films with tunable optical properties. This study reports the first example of tuning the optical properties of a MOF-based optical thin film via post-modification. The MOF-based optical thin film was composed of NH2-MIL-53(Al) nanorods (NRs) (MIL: Materials from Institute Lavoisier), and was constructed via a spin-coating method. Three aldehydes with different lengths of carbon chains were chosen to modify the MOF optical thin film to tune their optical properties. After post-modification, the structural color of the NH2-MIL-53(Al) thin film showed an obvious change from purple to bluish violet and cyan. The reflection spectrum and the reflectivity also altered in different degrees. The effective refractive index (neff) of MOFs thin film can also be tuned from 1.292 to 1.424 at a wavelength of 750 nm. The success of tuning of the optical properties of MOFs thin films through post-modification will make MOFs optical thin films meet different needs of optical properties in various optical and optoelectronic devices.