Yang Yang,Siyu Huang,Jun Li,Xinjia Yang,Qiu Zhang,Liying Pan,Xueyue Lyu,Guangdong Zhao
In order to mitigate the adverse effects of electromagnetic pollution, there is an increasing demand for high-performance electromagnetic absorbing materials. Ceramic materials are gained widespread application in the domain of electromagnetic absorption due to their excellent resistance to high temperature, corrosion, and oxidation. This paper presents the design and synthesis of a SiC/TiC ceramic with superior electromagnetic absorption properties, achieved through the polymer-derived ceramics (PDCs) method. In this process, phenolic resin was employed as the carbon source, titanium isooctylate served as the titanium source, and chloromethyl dimethyl chlorosilane was utilized as the silicon source. The ceramic material exhibited optimal wave absorption characteristics at a Si:Ti ratio of 5:1. At a matching thickness of 2.0 mm, the maximum effective absorption bandwidth reached 3.45 GHz (ranging from 10.69 to 14.14 GHz), with a minimum reflection loss (RL) value of −42.8 dB, indicating that 99.992 % of the electromagnetic wave was absorbed by the SiC/TiC ceramic material. This study offers an effective strategy for the design of electromagnetic absorbing ceramic materials.
Due to their high melting point, low density, and affordable price, TiC ceramics have emerged as one of the most promising ultrahigh temperature structural materials. However, its development and usage are severely constrained by its weak mechanical characteristics. The Ti2AlC-TiC and Ti3AlC2-TiC composites were synthesized by using the laminated metal-ceramic Ti2AlC/Ti3AlC2 as the binder, combined with high-temperature and high-pressure sintering technology (GPa order of magnitude confinement system). The thermal analysis shows that the exothermic heat of Ti/1.2Al/2TiC is less than that of 3Ti/1.2Al/2C, 2Ti/1.2Al/C, and 3Ti/1.5Al/C. The ratio of Ti/1.2Al/2TiC can suppress the thermal explosion phenomenon during the sintering process and improve the safety of the high-pressure sintering process. XRD results showed that the main composition of the sintered products was Ti2AlC-TiC at 2∼3.5 GPa and Ti3AlC2-TiC at 4∼5 GPa. As the sintering pressure increased from 2 GPa to 5 GPa, the bonding phase changed from Ti2AlC to Ti3AlC2. The thickness of the synthetic Ti3AlC2 layer is near 0.1 µm under 5 GPa. The average friction coefficient of Ti2AlC-TiC composites sintered 2 GPa with POM is as low as 0.1767, while the average friction coefficient of Ti3AlC2-TiC composites with POM increased to 0.3468∼0.3797. The wear width of Ti2AlC-TiC is lower than that of Ti3AlC2-TiC composites sintered under 4–4.5 GPa. The wear width of Ti3AlC2-TiC composites decreases following the rise of sintering pressure and is reduced to 0.3504 mm under 5 GPa. Ti2AlC-TiC and Ti3AlC2-TiC composites with PP ball counterparts have friction coefficients of 0.375 to 0.45 and worse wear resistance than that of POM balls. Ti3AlC2-TiC composites synthesized at 5 GPa with a Cu ball had the smallest friction coefficient (0.4558) and the smallest wear scar width (0.6289 mm). The friction coefficients and wear widths of synthetics with Al pairs ranged from 0.48–0.697 and 0.851–1.087 mm, respectively, and varied irregularly with increasing sintering pressure. Ti2AlC-TiC composites synthesized at 2 GPa with agate and glass pairs have coefficients of friction of 0.5 and 0.61, respectively. Abrasion widths of Ti2AlC-TiC composites synthesized at 2 GPa with agate and glass pairs were 1.3 mm and 0.72 mm, respectively. The friction coefficient of synthetics with agate and glass pairs increases with increasing sintering pressure. The magnetization and magnetization intensity of the Ti3AlC2-TiC composites are stronger than those of Ti3AlC2. Ti2AlC-TiC and Ti3AlC2-TiC composites held promise to serve in the field of ceramic grinding processing applications.
危险品化学品经营许可证（带存储）