超声空化对陶瓷刀具材料晶粒生长的影响

Effect of ultrasonic cavitation on grain growth of ceramic tool materials

为了研究超声无压烧结陶瓷刀具材料时超声空化对晶粒生长的影响,分析了气孔在熔融金属中发生超声空化的条件,建立了含有空化泡的晶粒模型,讨论了超声空化对晶粒的作用,并采用蒙特卡罗法模拟了未施加和施加超声下的晶粒生长过程,研究了超声空化对晶粒生长过程的影响。结果表明:当空化泡的半径介于1μm~2μm时,超声波的声压阈值为8.02×10^(6)Pa,频率阈值为2.00×10^(6)Hz;超声空化可增大晶格振动频率和振动能量,阻碍晶粒生长,起到细化晶粒和减小孔洞的作用。

To investigate the effect of the ultrasonic cavitation on the grain growth of the ceramic tool materials during the ultrasonic pressureless sintering,the cavitation effect of bubbles in the molten metals was studied,the grain model containing the cavitation bubbles was established,and the grain growth process without and with ultrasound was simulated by Monte Carlo method.The results show that,the threshold of sound pressure is 8.02×10^(6)Pa and the threshold frequency is 2.00×10^(6)Hz when the radius of the cavitation bubble is between 1μm and 2μm.Furthermore,the ultrasonic cavitation can increase the vibration frequency and vibration energy of the lattice,which hinders the growth of the crystal grains,refines the grains,and reduces the pore size.