共查询到17条相似文献,搜索用时 78 毫秒
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Ar,Ti离子注入Si3N4表面改性的研究 总被引:6,自引:0,他引:6
研究了Si3N4陶瓷及其表面蒸镀Al膜试样的离子注入效果,结果表明,Ti离子的注入与Ar离子的注入都可提高Al膜与陶瓷基体的结合力,并在一定的注入的剂量范围内随着注入剂量的增加,Al膜与陶瓷基体的结合力也有增加的趋势。Ti离子的注入使表面硬度增加,表面硬度随Ti离子注入量的增加而提高。Ar离子的注入(10^15Ions.cm^-2)也使表面硬度增加,但继续增加Ar离子的注入量,表面硬度却下降。根据 相似文献
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纳米Si3N4粉体表面改性及其在橡胶中的应用研究 总被引:1,自引:0,他引:1
该文选择含羧基(-COOH)和腈基(-CN)的聚合物作为表面改性剂,研究了对纳米Si3N4粉体湿法改性工艺的影响因素,采用TGA对纳米Si3N4粉体改性效果进行了表征,确定了最佳改性时间(120min左右)、改性温度(60℃左右)和改性剂用量(5%左右)。把在此工艺条件下表面改性后的纳米Si3N4粉体加入橡胶中,当改性纳米Si3N4粉体的用量为生胶的0.5%(质量比)时,所制备的Si3N4/NBR复合材料的撕裂强度、拉伸强度、耐油性能均得到明显的提高。 相似文献
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采用羟基化结合硅烷偶联剂(KH560)对氮化硅(Si3N4)粉体进行表面功能化改性,配制出高固含量、高固化深度的Si3N4膏料,并基于立体光固化(SL)工艺制备了高强度的Si3N4复杂结构件。结果表明:Si3N4表面的KH560改善了粉体与树脂的相容性,降低了Si3N4膏料的粘度;同时,KH560的环氧基团(—CH(O)CH2)与环氧树脂(EA)通过化学键等方式相结合,形成了EA核壳结构,降低了树脂与陶瓷颗粒之间的折射率差,从而提高了Si3N4膏料的固化深度。表面羟基化处理后Si3N4表面吸附了更多的KH560,从而进一步降低了Si3N4膏料的粘度,提高了Si3N4膏料的固化深度。最终,用羟基化和KH560改性后的Si3N4粉体配制出的Si3N4膏料固含量达到50%(体积分数),固化深度达到64 μm。烧结后Si3N4试样致密度为83%,断裂韧性为(4.38±0.45) MPa·m1/2,抗弯强度达到(407.95±10.50) MPa。 相似文献
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纳米氮化硅粉体的表面改性研究 总被引:1,自引:0,他引:1
硅烷偶联剂KH550和KH560分别对纳米Si3N4粉体进行表面改性,通过测定改性后纳米Si3N4粉体的活化指数来筛选最佳改性工艺,并评价其分散性。用激光粒度分析仪和傅立叶变换红外光谱仪(FTIR)探测纳米Si3N4粉体的表面改性效果。结果表明:当KH560的添加量为Si3N4的10%,采用60℃×3h工艺改性,活化指数能达到85%以上,改性效果最佳。 相似文献
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利用EPMA和XRD的分析方法,研究了Si_3N_4陶瓷材料表面氧化层的组成。结果表明,Si_3N_4陶瓷材料表面的氧化层,是由方石英相和含有Al_2O_3、CaO等杂质的SiO_2玻璃相所组成。其中SiO_2玻璃相中Al_2O_3、CaO等杂质的含量,随着氧化时间的增加而逐渐增加。 相似文献
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液体介质对氮化硅粉料表面基团和悬浮特性的影响 总被引:7,自引:1,他引:6
利用漫反射Fourier变换红外光谱(DRIFT)技术,研究了液体介质(水,乙醇和丙酮)对氮化硅粉料表面基团的改变和对其悬浮特性的影响。结果表明,氮化硅粉料在不同的液体介质中球磨中,粉料的表面基团和悬浮特性的变化各不相同,去离子水介质球磨的粉料,颗粒表面的Si-OH基团消失,Si-O-Si和Si-H基因数量减少,使粉料的悬浮特性有所提高,乙醇介质中处理的氮化硅粉料,颗粒表面生成稳定的Si-O-C-R表面官能团,使粉料的悬浮性能降低,丙酮介质中处理的氮化硅粉料,在颗粒表面生成Si…0=C/(CH3)2基因,使粉料在水中的分散性大为下降,这种键合不稳定,在200℃干燥时大部分会断开消失,少量键合转变成稳定的Si-O-C-R形成;3种液体介质球磨改性的粉料,在600℃,6h煅烧之后,其DRIFT谱图基本相同,同时表现出几乎相同的流变特性。 相似文献
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针对高精密氮化硅陶瓷器件的需求,采用金属蒸发真空电弧离子注入机进行金属Al+3注入Si3N4,并对其抗氧化性能进行了研究.注入能量为40 keV,注入剂量分别为5×1016 ion/cm2和2×1017 ion/cm2.在1 200 ℃,长达77 h,对Si3N4的循环氧化行为进行了实验研究.用SEM,XRD和EDS等方法对样品进行了观察和分析.结果表明Al+3注入提高了Si3N4样品的抗氧化性能,氧化质量变化符合抛物线规律.原始Si3N4样品的氧化层较厚,与基体有较明显的分层现象;注入铝的Si3N4试样氧化层较薄和致密,与基体没有明显的分层现象,电子价态分析表明注入的金属铝形成的氧化铝是提高Si3N4抗氧化性能的主要原因. 相似文献
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《Ceramics International》2023,49(16):27040-27049
Porous Si3N4 ceramics with high strength and high transmittance have been widely used in the field of defense and military. Additive manufacturing (AM) technology is one of the effective means to fabricate porous Si3N4 ceramics. Nevertheless, it is difficult to prepare porous Si3N4 ceramics by using digital light processing (DLP) because of the large refractive index difference between Si3N4 powders and photosensitive resin. In this study, the effects of the amount of polystyrene (PS) powders on the properties of Si3N4 ceramic slurries and sintered ceramics were systematically discussed. The addition of PS reduced the overall refractive index of powders and increased the average particle size of powders, thus improving the cure depth of Si3N4 ceramic slurries from 11.0 ± 2.0 μm to 55.7 ± 1.8 μm. With the increase of PS content, the shrinkage and porosity of Si3N4 ceramics gradually increased, and the bulk density and flexural strength showed the opposite trend. The slurry with low viscosity (2.38 Pa٠s at a shear rate of 30 s−1) and high cure depth (51.2 ± 4.6 μm) was obtained when the content of PS was 15 wt%, which met the thickness requirements for printing. The total porosity of Si3N4 ceramics reached the maximum values at 28.21 ± 2.58%. The addition of PS solved the problem of low cure depth of slurries, and PS as a pore-forming agent could help Si3N4 ceramics form porous structure. This research provides valuable insights into the fabrication of non-oxide ceramics with high refractive index using DLP technology. 相似文献
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Si3N4@(TiN–Si3N4) composites with heteroshelled structure were designed for enhanced conductivity and successfully synthesized through the simultaneous reduction and in‐situ cocoating process in liquid ammonia at around ?40°C. The heteroshells were composed of nanosized TiN and Si3N4 particles, which were amorphous with the size ranging from 10 to 40 nm. Using spark plasma sintering, dense bulk composite with >98.1% relative density of theoretical value were obtained and their electrical conductivity were increased to an adequate value (6.62 × 102 S·cm?1) for electrical discharge machining by compositing 15 vol% TiN to Si3N4, which is superior to the previous reports. The excellent electric performance could be attributed to the heteroshelled structure which guarantees the conductive network can be formed and kept with minimal TiN content. The nanosized Si3N4 powders in the shells reduce the content of conductive powders and limit the growth of TiN particles. 相似文献
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Si3N4/TiC纳米复合陶瓷刀具材料氧化行为 总被引:1,自引:0,他引:1
在微米Si3N4基体中加入纳米Si3N4及TiC颗粒,以Al2O3和Y2O3作为助烧结剂,通过热压烧结制备了Si3N4/TiC纳米复合陶瓷刀具材料,研究了该材料在800~1 250℃时的氧化行为.结果表明:该类材料的氧化特性符合抛物线规律;随TiC含量的增加,材料的抗氧化性能降低.由氧化后样品的X射线衍射谱分析可知:氧化表面生成SiO2和TiO2,表面仅余微量的Si3N4和TiC成分,表明经1 250℃,100h氧化后,样品表面几乎被氧化物覆盖.Si3N4/TiC(含有10%纳米Si3N4和15%TiC,质量分数)纳米复合材料在经过900℃,100h氧化后,其强度无明显下降;但经过1000℃,100h的氧化后,材料的强度已经降至氧化前的41%.扫描电镜观察表明裂纹的生成及扩展是引起强度降低的主要原因. 相似文献