Inorganic coating was fabricated on the surface of the porous Si3N4 ceramic by polymer derived（PD） and spraying technology, via using vinyl-polysilazane（PSN-1） as a preceramic polymer and Si3N4 and lithium alumino...Inorganic coating was fabricated on the surface of the porous Si3N4 ceramic by polymer derived（PD） and spraying technology, via using vinyl-polysilazane（PSN-1） as a preceramic polymer and Si3N4 and lithium aluminosilicate（LAS） powders as fillers. The phase and microstructure of the coatings were analyzed by X-ray diffraction（XRD） analysis and scanning electron microscopy（SEM）, respectively. The effect of the coatings on mechanical property and humidity resistance of the porous Si3N4 ceramic was investigated. The experimental results showed that we successfully fabricated the uniform and dense coating which preferably combined with the substrate upon the addition of fillers. The bending strength of the porous Si3N4 ceramic sprayed the coating increased by more than 18%, and the surface hardness increased by 1.7 times. The apparent porosity of the materials reduced by an average of 97.7%, and water absorption was below 0.5%. Therefore, the prepared coating with preferable density had an obviously moisture-proof and enhanced effect on the porous Si3N4 ceramic.展开更多
Construction materials and layered design are the indispensable part of construction drawing design. If the design is not correct, seriously, it will affect the safety of peoples lives and property. This paper sums up...Construction materials and layered design are the indispensable part of construction drawing design. If the design is not correct, seriously, it will affect the safety of peoples lives and property. This paper sums up some common problems found in the course of my work about this aspect of drawings, and hopes to play a better guiding role in the optimization and improvement of this aspect of drawings. The following contents refer to "building construction materials and layering practices" as "building construction practices".展开更多
文摘Inorganic coating was fabricated on the surface of the porous Si3N4 ceramic by polymer derived（PD） and spraying technology, via using vinyl-polysilazane（PSN-1） as a preceramic polymer and Si3N4 and lithium aluminosilicate（LAS） powders as fillers. The phase and microstructure of the coatings were analyzed by X-ray diffraction（XRD） analysis and scanning electron microscopy（SEM）, respectively. The effect of the coatings on mechanical property and humidity resistance of the porous Si3N4 ceramic was investigated. The experimental results showed that we successfully fabricated the uniform and dense coating which preferably combined with the substrate upon the addition of fillers. The bending strength of the porous Si3N4 ceramic sprayed the coating increased by more than 18%, and the surface hardness increased by 1.7 times. The apparent porosity of the materials reduced by an average of 97.7%, and water absorption was below 0.5%. Therefore, the prepared coating with preferable density had an obviously moisture-proof and enhanced effect on the porous Si3N4 ceramic.
文摘Construction materials and layered design are the indispensable part of construction drawing design. If the design is not correct, seriously, it will affect the safety of peoples lives and property. This paper sums up some common problems found in the course of my work about this aspect of drawings, and hopes to play a better guiding role in the optimization and improvement of this aspect of drawings. The following contents refer to "building construction materials and layering practices" as "building construction practices".
