Materials Research and Development is an international, peer-reviewed open access journal dedicated to advancing research the field of materials science and engineering. The journal provides a rapid publication process to ensure wide dissemination of high-quality articles to scientists, professionals, and interested individuals worldwide. Our goal is to serve as an efficient, reliable, and trusted platform for scholars and readers, publishing cutting-edge research in the field.
Abstract: Polyimide (PI) is one of the engineering plastics with excellent comprehensive properties. Currently, its preparation and application technology are closely related to a large number of cutting-edge technologies and products. Therefore, PI is listed in the category of key development materials in the ‘13th five-year plan’ of China. In te meantime, the production technology of high-performance PI is tightly controlled by a few international enterprises. On the other hand, PI related industries in China are established late and small in production scale, lacking the mastery of core technology, which make the production and application of PIs the "neck-clamping" technology, which needs to be developed urgently in China. In this paper, the classification and preparation methods of PI, as well as the development status and main product categories of PI manufacturers at home and abroad are summarized. It is explicit that foreign enterprises have rich PI product lines and wide product coverage, while China's PI industry has rich commodity products with overcapacity, but in shortage of high-end products. Essentially, although our industry has clear understanding of the PI synthetic fundamentals, the key-technical know-hows are leg behind and a large gap in production processes exists compared with the mature foreign producers. However, under the advantageous national policies guidance and supports, China's PI industry is now in a favorable developing environment and should be enjoying a rapid growth period.Abstract: Polyimide (PI) is one of the engineering plastics with excellent comprehensive properties. Currently, its preparation and application technology are closely related to a large number of cutting-edge technologies and products. Therefore, PI is listed in the category of key development materials in the ‘13th five-year plan’ of China. In te meantime, ...Learn More
Abstract: In order to solve the problem that the irregular pore structure of the surface of porous bioceramic coating prepared by laser cladding under a certain optimized optimal process parameters is difficult to describe with traditional Euler geometry. In this paper, the pore structure morphology of the bioceramic coating surface was tested by scanning electron microscopy (SEM) creatively, and the SEM image of the coating surface was processed to statistically analysis the pore structure parameters by the picture software Image J, and then the fractal dimension (Df) of the pore structure was tested by the classic area-perimeter (A-P) method, and the irregular pore structure was successfully systematically described. The research results show that the principle of the method is simple and operable, and the pore structure of the coating in the range of 2.5-10wt.% can be described by the Df value, which is related to the size and the complexity of the pore structure of the bioceramic coating. Corresponding to the pore structure of the 2.5, 5, 7.5 and 10wt.% bioceramic coating respectively, the fractal dimensions is 1.344, 1.352, 1.394 and 1.34, respectively. In which, the Df value of the 7.5wt.% coating is the highest, it was suggested that pore structure of the coating with 7.5% pore additive addition also has the largest number of pores in the most complex pore structure.Abstract: In order to solve the problem that the irregular pore structure of the surface of porous bioceramic coating prepared by laser cladding under a certain optimized optimal process parameters is difficult to describe with traditional Euler geometry. In this paper, the pore structure morphology of the bioceramic coating surface was tested by scanning el...Learn More
Abstract: With the rapid development of energy, information, environmental protection and biological science and technology, the material with a long history-ceramics, has also obtained a new research progress, namely, the development of functional ceramics. Functional ceramics play a key role in related scientific research and engineering project applications, with their unique thermal, electric, magnetic, acoustic and optical physical characteristics, chemical, biological and appropriate mechanics characteristics. Moreover, because the photocatalytic technology has the characteristics of mild reaction conditions, convenient operation and no secondary pollution, it is considered as the most promising environmental governance technology in the 21st century, that is, it can effectively solve the problems of fossil energy depletion and environmental pollution. In addition, photocatalytic technology also has the characteristics of low energy consumption, and has also become a necessary technology to develop new energy sources. If functional ceramics and photocatalytic technology are combined together, it will solve many problems in industrial production and life. A variety of materials with photocatalytic characteristics in functional ceramics have been developed. This paper mainly expounds the performance research and its development and application of Ti-based functional ceramic photocatalytic materials, multiple material composite ceramic photocatalytic materials and tungsten-based activated carbon-based ceramic photocatalytic materials.Abstract: With the rapid development of energy, information, environmental protection and biological science and technology, the material with a long history-ceramics, has also obtained a new research progress, namely, the development of functional ceramics. Functional ceramics play a key role in related scientific research and engineering project applicatio...Learn More
Abstract: The burning of fossil fuels has caused increasingly serious environmental pollution. As a new energy conversion device, fuel cell involves oxygen electrocatalytic reaction, but these reaction processes are complicated and high overpotential, so it is necessary to find suitable catalyst to promote the smooth reaction. The reactants O2 and N2 of oxygen reduction reaction (ORR) and nitrogen reduction reaction (NRR) all come from air, while the products H2O and NH3 are important chemical resources. In this paper, the selective adsorption of O2/N2 by 13 kinds of non-expensive transition metals (TM) anchored by graphene under different N concentration doping conditions was studied by calculation. It was concluded that the higher the content of N in single-vacancy and double-vacancy structures, the better the stability of the substrate, and the stability of the double-vacancy structure is better than that of the single vacancy. The ZrN4 catalytic substrate with the best stability was mainly studied. Through the Mulliken charge distribution and partial wave density of state (PDOS), it was found that its charge distribution was symmetrical and the electron transfer was obvious. Further analysis of the deformed state density of the substrate adsorbing O2 and H2O shows that the catalytic substrate has excellent adsorption and desorption capacity. Except CuN0C4, ZnN0C4, CdN4C0, CdN2C2-o and ZnN2C1 substrates, the other structures have moderate adsorption capacity of reactant O2 and desorption capacity of product H2O, which are potential sources of ORR catalysts in acidic environment.Abstract: The burning of fossil fuels has caused increasingly serious environmental pollution. As a new energy conversion device, fuel cell involves oxygen electrocatalytic reaction, but these reaction processes are complicated and high overpotential, so it is necessary to find suitable catalyst to promote the smooth reaction. The reactants O2 and N2 of oxyg...Learn More
Abstract: In order to reasonably design the composition of Al-Si based alloy and study the effect of alloying elements on hot crck of Al-Si based alloys, the effect of alloying elements on hot cracking of Al-Si based alloy was studied. The influence of different Si contents on the crack susceptibility index (CSI) of Al-Si alloy was calculated by using Pandat, and the influence of Mg addition on the CSI of the Al-Si-Mg alloy was also calculated. The solidification path affecting the CSI of the alloy was analyzed. The results show that when the Si content is below 10% (mass percentage), the CSI is almost non-existent and the Al-Si alloy will not show crack tendency; When the Si content reaches 11~12%, the CSI of the Al-Si alloy is very small. When the Si content reaches the hypereutectic region (Si ≥ 13%), the CSI of the Al-Si alloy begin to increase with increasing of Si content. The crack tendency of the Al-Si alloy in the hypereutectic region is larger. Adding Mg can effectively reduce the CSI of the alloy. Furthermore, with increasing of Mg content, the CSI of Al-Si-Mg alloy gradually decreases.Abstract: In order to reasonably design the composition of Al-Si based alloy and study the effect of alloying elements on hot crck of Al-Si based alloys, the effect of alloying elements on hot cracking of Al-Si based alloy was studied. The influence of different Si contents on the crack susceptibility index (CSI) of Al-Si alloy was calculated by using Pandat...Learn More
Abstract: Transparency is a common pathology in aged teeth due to the dentin tubules are filled up with mineral crystals. The mechanical properties of dentin are also affected by ultrastructure changed in the aged dentin. Nanoindentation test is a popular technique to assess the elastic mechanical properties of dentin, while it’s difficult to obtain inelastic mechanical parameters since the indenter tip caused a complex stress distribution within dentin. The plastic-damage model incorporating finite element method is adopted to characterize the plastic and damage behaviors of dentin based on the nanoindentation experiments. The numerical simulations indicate that yield strength of dentin increased with aging. The capacity for energy dissipation via inelastic deformation which reflects the materials’ toughness decreases with increase of age. In addition, the numerical simulations also show that the magnitude of damage decreases with aging. The degradation of the unloading stiffness was caused by the damage at beneath the indenter.Abstract: Transparency is a common pathology in aged teeth due to the dentin tubules are filled up with mineral crystals. The mechanical properties of dentin are also affected by ultrastructure changed in the aged dentin. Nanoindentation test is a popular technique to assess the elastic mechanical properties of dentin, while it’s difficult to obtain inelasti...Learn More
