共查询到19条相似文献,搜索用时 78 毫秒
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钛酸铝材料反常热膨胀特性的分析研究 总被引:6,自引:0,他引:6
铁稳定钛酸铝材料在850 ̄950℃之间热膨胀有一个特殊变化,即出现反常负膨胀。本研究通过对试样的热膨胀分析、X-RAY分析和SEM分析,探明了造成这一变化的原因。 相似文献
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钛酸铝陶瓷热膨胀机理研究 总被引:6,自引:0,他引:6
本文运用了电镜观察、显微结构分析、再加热条件下的热膨胀实验等方法,对钛酸铝陶瓷材料的热膨胀机理进行分析、研究,指出升温时由于微裂纹的弥合导致Al2TiO5陶瓷有较小的热膨胀系数。并着重研究了钛酸铝陶瓷降温时的收缩机理,指出Al2TiO5陶瓷的降温曲线有一最低点,在最低点右边,由于降温收缩造成的内应力还不足以造成大多数晶界和晶粒上发生微裂纹,Al2TiO5陶瓷随着温度的下降而收缩,在最低点左边,由于 相似文献
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以铁合金厂铝钛渣为主要原料,通过固相反应烧结法制备钛酸铝材料,研究了锆英石对不同温度煅烧所得钛酸铝材料的分解率及烧结性能的影响。利用X射线衍射(XRD)、扫描电镜(SEM)及相关分析软件对煅烧后试样的相组成、晶胞参数、相对结晶度及微观结构进行分析。结果表明,锆英石中Zr4+和Si4+对钛酸铝中Ti4+的置换行为加速了钛酸铝材料的固相反应,加入氧化锆有利于降低钛酸铝材料的分解率,提高钛酸铝材料的致密度。升高煅烧温度可以增强锆英石对钛酸铝材料性能的影响,抑制钛酸铝材料的分解。 相似文献
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复合添加剂抑制钛酸铝热分解的作用及其机理的研究 总被引:5,自引:0,他引:5
本文采用X衍射分析,热膨胀分析,透射电镜和电子探针分析详细研究了复合添加剂抑制钛酸铝热分解的作用和机理。研究表明,复合添加剂抑制钛酸铝热分解的效果比单一添加剂的效果更为显著。复合添加剂不仅提高了钛酸铝的热稳定性,而且还保持了其优良的低膨胀特性。 相似文献
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Yunfei Huang Dongjiang Wu Xuexin Yu Guangyi Ma Jun Han Hong Wang Fangyong Niu 《Journal of the American Ceramic Society》2023,106(7):4358-4370
Thanks to its advantages of high efficiency and near-net shaping, laser directed energy deposition (LDED) is rapidly becoming a remarkable preparation technology for high-purity ceramics. However, the cracking problem in shaping process is always a great challenge for LDED to achieve industrial application. For this purpose, alumina/aluminum titanate melt-growth ceramics (A/AT MGCs) were prepared using LDED system, and the corresponding finite element thermal analysis model was developed. The solidification behavior and cracking mechanism of A/AT MGCs were investigated based on the thermal analysis model, and the influence of process parameters on the cracking characteristics was revealed with experiments. Results show that the crack morphology and distribution are controlled by microstructure and temperature gradient together. The scanning speed of 100–150 mm/min, with better microstructure and lower temperature gradient, is a preferred process window. This study provides theoretical guidance and technical support for the cracking suppression during LDED shaping of ceramics. 相似文献
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综述了BaTiO3的研究进展,从BaTiO3的介电常数和化学掺杂出发,重点介绍了目前国内外BaTiO3的制备方法及其特点,最后展望了BaTiO3的发展趋势。 相似文献
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Xuehui Huang Xinke Yang Xuefang Wang 《International Journal of Applied Ceramic Technology》2023,20(5):2974-2984
Using Al2O3 and TiO2 as raw materials, adding MgO as heat stabilizer and mullite as enhancer, aluminum titanate-mullite multiphase ceramics were successfully prepared by solid phase synthesis. The effects of MgO and mullite were systematically studied on the phase composition, microstructure, thermal stability, sintering properties, and mechanical properties of aluminum titanate ceramics. The results showed that the introduction of Mg2+ can partially replace Al3+ to form MgxAl2(1-x)Ti(1+x)O5 solid solution, improved the thermal stability of aluminum titanate ceramics, and promoted the formation and growth of grains, which reduced the sintering temperature. The crack deflections caused by mullite particles improved the mechanical properties. The filling effect of mullite particles and the formation of silica in mullite raw materials were conducive to ceramic densification. The statistics of Mg4M10 sample were as follows: the porosity was only 2.9%, the flexural strength was as high as 64.15 MPa, and the thermal expansion coefficient was 1.35 × 10−6 K−1 (RT-700°C), encouraging the application of ceramics with high thermal mechanical properties. 相似文献
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