【摘要】 SiC木质陶瓷是近年来应用前景广阔的新型陶瓷材料,以绿色可再生的木材为原材料,通过反应烧结工艺制备出的陶瓷具有优良的高温力学性能。为探究影响生物质陶瓷性能的因素,将黄杨木在800℃氮气保护下热解形成生物质炭坯,然后在1 650℃和1 900℃两种高温下进行熔融渗硅制备SiC木质陶瓷。利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)研究SiC木质陶瓷的物相组成和微观结构,采用阿基米德排水法和三点弯曲法测定陶瓷的开孔率、密度和弯曲强度,再使用维氏硬度计测定SiC木质陶瓷的显微硬度。研究结果表明:在1 650℃下通过熔融渗硅可以得到微观结构均匀的SiC木质陶瓷,在1 650℃比在1 900℃下熔融渗硅制备陶瓷的力学性能更优异,陶瓷的密度更大,为2.27 g/cm~3,此时弯曲强度为192.45 MPa;游离Si会提高SiC木质陶瓷的密度,增强陶瓷的弯曲强度。更多还原

【Abstract】 SiC woodceramics is a new type of ceramic material with broad application prospects in recent years. Using green and renewable wood as the original material, the ceramics fabricated by the reaction sintering process has excellent high-temperature mechanical properties. In order to explore the factors that affect the properties of biomass ceramic materials, boxwood was pyrolyzed under the protection of nitrogen at 800 ℃ to form a biomass carbon template, and then SiC woodceramics were fabricated by liquid silicon infiltration at 1 650 ℃ and 1 900 ℃. In order to determine the prepared materials and their properties, the phase composition and microstructure were studied with X-ray diffraction(XRD) and scanning electron microscopy(SEM), the porosity and density were measured by Archimedes drainage method, the bending strength of ceramics was measured by three-point bending method, and the microhardness was determined by Vickers hardness tester. The results show that SiC woodceramics with uniform microstructure are fabricated by liquid silicon infiltration at 1 650 ℃. The mechanical properties and density(2.27 g/cm~3) of ceramics fabricated by liquid silicon infiltration at 1 650 ℃ are better than those fabricated at 1 900 ℃, and the bending strength is 192.45 MPa. The free Si increases the density of SiC woodceramics as well as enhances the bending strength and microhardness.更多还原