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爆轰合成纳米超微金刚石的热稳定性研究 总被引:1,自引:0,他引:1
用差热、热失重和X射线衍射分析对爆轰合成纳米超微金刚石的热稳定性进行了研究,分析了不同合成和提纯条件以及不同气氛对超微金刚石热稳定性的影响。研究结果表明,纳米超微金刚石在空气氛中的热稳定性较差,其起始氧化温度为500~530℃;在惰性和还原性气氛中具有较好的热稳定性;包裹水条件下得到的金刚石及用H2SO4+KMnO4提纯得到的超微金刚石的热稳定性较好。 相似文献
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自蔓延预热爆炸固结Mo/Cu功能梯度材料的研究 总被引:2,自引:0,他引:2
设计并采用自蔓延燃烧预热,水介质缓冲双向爆炸固结的方式制备了Mo/Cu功能梯度材料(FGM),观测了Mo/Cu FGM的显微组织并分析了固结过程。对各层的密度、硬度、电导率等进行了测量和分析。发现随着Cu含量的增多,材料的密度平缓递减但相对密度逐渐增大,硬度降低,电导率升高。相对密度从Mo层的94.2%到Cu层的98.4%,试样整体的相对密度达95.5%。Mo/CuFGM第1层与第2层间的剪切强度为214.8MPa;Mo/CuFGM第3层,第4层的热导率分别为204.76W·m^-1·K^-1和249.71W·m^-1·K^-1。 相似文献
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A long-pulse low-velocity gas gun with a gas buffer is used to induce impact damage in cast Composition B and hot pressed PBXN-5. To obtain different damage states, a range of projectile velocities are used by control-ling the launching pressure of gas gun. The stress history during impact loading is recorded. Various methods are used to characterize the damage state of impacted explosive samples. The microstructure is examined by use of scanning electronic microscopy (SEM) and polarized light microscopy (PLM). The densities and ultrasonic atten-uation are also measured. The results show that both Composition B and PBXN-5 exhibit some damage character-istics of brittle materials. However, due to the difference in compositions, PBXN-5 exhibits better resistance to impact loading than Composition B. 相似文献
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