超声波对液相烧结初期致密化行为的影响

Effects of Ultrasonic Wave on Densification Behavior in Initial Stage of Liquid Phase Sintering

为改善烧结材料的致密性以提高陶瓷材料的综合性能,研究了超声波作用下固相颗粒在液相中的受力及致密情况。根据粉末液相烧结原理,构建了颗粒在液相中的受力图,依据固相颗粒在液相中的受力分析,建立了烧结体系初期相对密度与毛细管力、外加压力和超声波声压间的关系。为了探明超声波对液相烧结初期致密度的影响,以TiB2-Ni烧结材料为研究对象,在1500℃、外加压力为30 MPa的条件下,计算了不同超声频率、液相粘度下的相对密度。结果表明:在超声波作用下,固相颗粒在液相中的驱动力增大,这有助于液相烧结的进行,有利于提高烧结材料的相对密度;当超声波频率增大时,烧结材料的相对密度变大;且在超声波作用下,液相粘度会降低,这有助于提高烧结材料的相对密度。

In order to improve the compactness of sintered materials and improve the comprehensive properties of ceramic materials, the stress and compactness of solid particles in liquid phase under the action of ultrasonic wave were studied. According to the principle of powder liquid phase sintering, the stress diagram of the particles in liquid phase was constructed. Based on the stress analysis of solid particles in liquid phase, the relationship among the initial relative density of sintering system and capillary force, external pressure and ultrasonic pressure was established. In order to find out the effects of ultrasonic wave on the initial densification of liquid phase sintering, taking TiB2-Ni sintered material as research object,under the condition of 1500 ℃ and applied pressure of 30 MPa, the relative density under different ultrasonic frequency and liquid viscosity was calculated. The results show that under the action of ultrasonic wave, the driving force of solid particles in the liquid phase increases, which is helpful to liquid phase sintering and increase the relative density of sintered materials.When the ultrasonic frequency increases, the relative density of sintered material increases;in addition, under the action of ultrasonic wave, the liquid phase viscosity decreases, which can help increase the relative density of sintered material.