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VPI法制备温度对Al2O3/水泥基材料组织和力学性能的影响

Characterization of Al2O3-Strengthened Cement Prepared by Vacuum Pressure Infiltration

  • 摘要: 以Al2O3颗粒来实现对水泥基材料的增强效果,通过真空压力浸渗法制得具有连续结构的Al2O3/Ce基材料,分析预热温度对材料显微组织及力学性能的影响。研究结果表明:随着处理温度的升高,Al2O3/Ce基材料达到了更大的致密度。随着预热温度的增加,试样孔洞数量减少,孔隙率减低。当预热温度600℃时,Al2O3/Ce基组织内形成了具有均匀粒径的颗粒,获得最优的浸渗效果。Al2O3颗粒具有良好耐热性以及耐蚀性能,经拉伸测试发现当预热温度上升后颗粒拉伸强度发生了减小。随着预热温度的增加,试样断口部位颗粒拔出长度减少,颗粒与界面间的结合能力增加。经过600℃预热试样形成了整齐的拉伸断口,裂纹在颗粒径向上发生了快速扩展,对承载面形成了贯穿,发生脆性断裂。

     

    Abstract: The Al2O3-strengthened cement,an advanced construction material,was prepared by vacuum pressure infiltration(VPI).The influence of the preheating temperature of powders on the microstructures and mechanical properties of the bulk Al2O3/Ce material was investigated with X-ray diffraction,scanning electron microscopy and conventional mechanical probes.The preliminary results show that the pre-heating temperature had a major impact.To be specific,as the pre-heating temperature increased from 480℃ to 600℃,both the compactness and inter-particle bonding of Al2O3/Ce material increased,accompanied by the decreases of the porosity,particle-size distribution and tensile-strength.In tensile measurement of the Al2O3/Ce sample preheated at an optimized temperature of 600℃,some the crack(s),formed at some weak spots,rapidly propagated in radial directions of grains,resulting in sharp tensile fracture because of brittle fracture mechanism.

     

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