金属铝粉和纳米Al2O3粉对陶瓷结合剂性能的影响

将金属铝粉、纳米Al₂O₃粉引入基础陶瓷结合剂,通过红外光谱分析陶瓷结合剂玻璃结构,X射线衍射表征其物相变化,并测试其耐火度,利用扫描电镜分析陶瓷结合剂立方氮化硼(CBN)复合材料的微观结构,并测试抗折强度,系统分析了金属铝粉、纳米Al₂O₃粉的单掺及复掺对陶瓷结合剂性能的影响。结果表明,金属铝粉使陶瓷结合剂耐火度升高,玻璃结构没有明显改变,部分铝粉转变为Al₂O₃,添加金属铝粉的陶瓷结合剂CBN复合材料抗折强度随烧结温度升高而提高。纳米Al₂O₃粉使陶瓷结合剂耐火度降低,呈玻璃相,但有少量Al₂SiO₅晶体和Li_xAl_xSi_3-xO₆晶体析出,添加纳米Al₂O₃粉的陶瓷结合剂CBN复合材料烧结温度720 ℃时出现较高抗折强度,达93.7 MPa。金属铝粉和纳米Al₂O₃粉的复掺有利于玻璃网络结构的键合,陶瓷结合剂以玻璃相为主,也有少量晶体析出,二者复掺对提高陶瓷结合剂CBN复合材料抗折强度更有优势,但烧结温度也相应升高,烧结温度740 ℃时抗折强度达最高值,为97.4 MPa。

Effects of Metal Aluminum Powder and Nano-Al2O3 Powder on Properties of Vitrified Bond

Metal aluminum powder and nano-Al₂O₃ powder were added to the basic vitrified bond. The glass structure was analyzed by infrared spectroscopy, the phase change was characterized by X-ray diffraction, and the refractoriness of vitrified bond was tested. The microstructure of vitrified bond CBN composite was analyzed by scanning electron microscope, and the bending strength of composite was tested. The effects of single doping and compound doping with metal aluminum powder and nano-Al₂O₃ powder on the performance of vitrified bond were systematically analyzed. The results show that the refractoriness of vitrified bond increases by adding metal aluminum powder, and the glass structure dose not change significantly. After sintering, part of the metal aluminum powder is transformed into Al₂O₃, and the bending strength of vitrified bond CBN composite increases with the increase of sintering temperature. The refractoriness of vitrified bond is reduced by adding nano-Al₂O₃ powder, and the vitrified bond is in glass phase, but a small amount of Al₂SiO₅ and Li_xAl_xSi_3-xO₆ crystals are precipitated, and a higher bending strength of 93.7 MPa of vitrified bond CBN composite is obtained sintering at 720 ℃. Compound doping of metal aluminum powder and nano-Al₂O₃ powder is beneficial to bonding of glass network structure. The vitrified bond is mainly glass phase, but a small amount of crystals are precipitated. Compound doping is more beneficial to increase bending strength of vitrified bond CBN composite, but the sintering temperature also increases accordingly. The highest bending strength of the composite sintered at 740 ℃ is 97.4 MPa.