Fe-WC料浆浇注过程中颗粒偏析的研究

Study on particle segregation in slip casting process

粉浆浇注过程中颗粒偏析现象是由细颗粒的堵塞效应和重力场的沉降作用共同决定的。通过深入分析粉浆浇注过程颗粒沉降运动规律,研究了颗粒偏析的本质。分析表明:粉浆浇注过程中的颗粒偏析与粉浆粘度η,液体介质流速v0、综合沉降因子r2ρ有关;提高粉浆粘度可以有效抑制颗粒偏析;降低液体介质流速可以抑制细颗粒堵塞效应。粉末装载量和石膏模具的膏、水质量比对颗粒偏析影响的试验结果与理论分析一致。

Particle segregation phenomena in slip casting process is controlled by clogging of fine particle and particle sedimentation in gravity field and its essence was studied by deeply analyzing sedimentary movement equation of particles.The analyses show that particle segregation is associated with apparent viscosity of slurry,flow velocity of liquid medium and integrative sedimentation factor of r2ρ.Particle segregation can be inhibited by increasing viscosity of slurry and clogging effect of fine particle can be inhibited by decreasing flow velocity of liquid medium.The effect of powder loading and ratios of plaster to water of the mould on particle segregation was studied.The experimental results are consistent with the predictions of theoretical analysis.