【作者】 李坤；

【导师】 王艳辉；

【作者基本信息】 燕山大学 ， 材料学， 2007， 硕士

【摘要】 本文主要包含两方面的工作:一是研制一种硼硅玻璃系高强度的陶瓷结合剂,优化烧结工艺和陶瓷结合剂配方,寻找抗折强度较高的陶瓷结合剂;二是研究陶瓷结合剂的气孔可控性,即以该陶瓷结合剂为基础,向其加入造孔剂,研究影响气孔率的相关因素。本文采用了冷压烧结法以硼玻璃、矿物A为主要原料,白刚玉为骨架相原料,烧制成SiO2-Na2O-B2O3体系陶瓷结合剂,研究了烧结工艺,优化了陶瓷结合剂配方。本文研究了玻璃化结合剂中氧化硼含量与其抗折强度之间的关系,研究了烧成温度、造孔剂粒度及其质量百分数对气孔率及气孔孔径的影响。本文用三点弯曲法测量陶瓷结合剂的抗折强度,运用X射线衍射和差热对陶瓷结合剂物相进行了分析;采用体式显微镜对气孔表面形貌进行了观察和分析。研究结果表明,以B2O3、SiO2和Al2O3为主要化学成分,配方10在烧成温度为900°C,等温烧结时间为2 h的条件下,结合剂的抗折强度为113.7 MPa,是一种抗折强度较高的陶瓷结合剂。向结合剂中添加金刚石烧结后,没有发生物相转变,故可以制作超硬磨具。结果表明:随着氧化硼含量的增加,结合剂的抗折强度先增加后减少,且满足R2O/B2O3=0.98和B2O3/SiO2=0.52的两条件时强度最高。用大理石颗粒在该结合剂中造孔,得到的气孔形状多为近球形,分布均匀,气孔直径分布在100~600μm之间。结合剂中的气孔率及孔径与烧成温度、造孔剂粒度及其质量百分数有关。气孔率可以通过改变造孔剂含量、烧结温度、造孔剂的粒度加以控制。在相同的烧结温度下,造孔剂含量越多气孔率越高,强度下降;在相同的造孔剂含量下,烧结温度升高,气孔率会增加,强度下降;在相同的烧结温度和造孔剂含量下,造孔剂的粒度增加,气孔率会下降,强度略微提高。更多还原

【Abstract】 This paper mainly focuses on two purposes: preparing porous vitrified bond with high strength, and managing to controll the porosity and the morphology of pores in the vitrified bond.The vitrified bond was prepared by cold pressing and sintering method using borosilicate, mineral A and white corundum as raw materials. Bending strength of vitrified bond was measured by three-point bending. XRD and stereomicroscope were carried to investigate the phase structure and the morphology of the pores. The relationship between the content of B2O3 and the bending strength of the vitrified bond which contains boron glass was established. The effects of sintering temperature, the contents and sizes of the pore former on the porosity and the morphology of pores were investigated.The experimental results show that high-strength vitrified bond whose main chemical components were B2O3, SiO2 and Al2O3 was obtained after sintering at the temperature of 900 oC for 2 hours. The bending strength reached 113.0MPa. With the increasing the B2O3 content, the bending strength tended to increase and then decrease. The optimum ratios of R2O/B2O3=0.98 and B2O3/SiO2=0.52. No chemical reaction was found when diamond grits added into the vitrified bond, showing that the bond was suitable for preparing the vitrified bond diamond tools.The spherical-like pores with the diameters of 100~600μm distributed uniformly in the bond when using marble as pore former. The porosity and the sizes of the pores depended on the sintering temperature, the content and granularity of the pore former. At the same sintering temperature and content, the results indicated that the porosity of the vitrified bond increased as the granularity of pore former decreased, while the strength of the bond induced a little bit.更多还原