排序方式: 共有63条查询结果,搜索用时 9 毫秒
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自蔓延高温合成锶铁氧体的研究 总被引:4,自引:2,他引:4
介绍了自蔓延高温合成技术合成SrFe12O19的工艺过程,对产物物相和性能进行了分析。将均匀混合后的原料直接在空气中点燃,并自发完成整个反应。合成产物经过后处理,用X射线衍射分析了产物的物相,用振动样品磁强计测试产物的磁性能,Hc为204.8kA/m,Ms为12.47emu/g。试验结果表明:SHS方法合成的SrFe12O19纯度高并具有良好的磁性能。同时介绍了用SHS方法合成锶铁氧体的一些影响因素,有原料中铁粉的含量、燃烧温度对燃烧过程和合成产物性能的影响。 相似文献
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张金咏 《武汉理工大学学报(材料科学英文版)》2011,26(4):681-683
In order to get a homogenous mixture and compact of TiB2-Al2O3, hybridization as a surface modification method was used to prepare nano-scale Al2O3 coated TiB2 particles. PE-wax particles were first coated onto TiB2 particles by hybridization, and then the nano-scale Al2O3 particles were coated onto the surface of TiB2 coated by PE-wax particles again. SEM, TEM and EDS were used to characterize the microstructure of as-received core/shell particles and its compacts. The experimental results show that a particle-scale homogenous dispersion of TiB2 and Al2O3 can be formed not only in mixed powder but also in dewaxed compacts. The compacts then were sintered by gas-pressing sintering (GPS). Finial products show improved mechanic properties comparing with reference samples fabricated by normal ways. 相似文献
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自蔓延高温合成细晶六硼化钙陶瓷粉末(英文) 总被引:1,自引:1,他引:0
基于Mg–B2O3–CaO原料体系,采用自蔓延高温合成(self-propagating high-temperature synthesis,SHS)和后期酸处理工艺,制备出高纯度、均匀分布、小粒径的立方晶型细晶六硼化钙粉末。分析了Mg–B2O3–CaO自蔓延高温反应体系的燃烧产物成分及反应机理,测量了不同SHS反应物原始坯体成型压力的燃烧温度曲线,探讨了不同镁掺量和不同气氛对燃烧产物成分和形貌的影响。研究了原始坯体成型压力与最终CaB6产物粒径的关系。结果表明:采用氩气保护能抑制镁挥发;合适的原始坯体压力有利于合成分布均匀的细晶CaB6粉末。 相似文献
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The damage mechanism and energy dissipation of the Polyethylene(PE) laminates in impacting was investigated. It was found that the dissipated energy of the impacting sphere bullet by the 1-mmthick PE plate firstly increased with the impacting velocity increasing from 50 to about 300 m/s, and then decreased with the impacting velocity increasing up to 600 m/s. According to the measured deformation and damage degree, a numerical simulation of the dissipated energy was made and obvious offset was found with the experimental results. The quasi-static properties of the PE fibers, decreasing with increase in tensile velocity, may be the main reason for the offset. 相似文献
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热分析结果表明,对于B2O3-TiO2-Mg-C体系,可利用SHS还原技术合成出TiB2-TiC陶瓷复合粉。其化学反应机理为:Mg先还原B2O3和TiO2,新生的Ti与B和C反应生成TiB2和TiC; TiO2的还原经历了TiO2→TiO→Ti的逐步过程。采用一定的酸洗工艺得到了纯净的TiB2-TiC陶瓷复合粉。复合粉中包含六方片状TiB2和圆球状TiC;复合粉中1μm以下颗粒质量百分数超过45%,87%以上的颗粒大小在3μm以下。在TiB2-TiC中,TiC<em>y以一种贫碳结构存在,物料中Ti被B或C结合形成TiB2和TiC<em>y,y的值为0.7483。 相似文献