Product Design of Cohesive Powders – Mechanical Properties, Compression and Flow Behavior
Product Design of Cohesive Powders – Mechanical Properties, Compression and Flow Behavior
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DOI：
10.1002/ceat.200406134
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发表时间：
2004-06
影响因子：
2.1
通讯作者：
J. Tomas
中科院分区：
文献类型：
--
作者：
J. Tomas
用颗粒力学和连续介质力学的合理结合解释了粘性粉末固结和流动行为的基本原理。通过刚性颗粒与软接触的模型，建立了具有黏着性的弹塑性和粘塑性颗粒接触行为、加载-卸载滞后和能量耗散、历史相关和非线性黏着力函数的通用模型。以此为物理基础，阐述了初期粉末固结、屈服和黏结稳态流动、固结和压缩函数、压缩和预剪工程。以超细石灰石粉为例，给出了其流动特性。这些本构模型用于评估剪切室试验结果，为设备设计提供依据，以确保可靠的粉末流动。最后，对加工行业的颗粒应力、粉体处理行为和产品质量评价等方面进行了总结。
The fundamentals of cohesive powder consolidation and flow behavior are explained using a reasonable combination of particle and continuum mechanics. By the model stiff particles with soft contacts, universal models are presented which include the elastic-plastic and viscoplastic particle contact behavior with adhesion, load-unload hysteresis and thus energy dissipation, a history-dependent and a nonlinear adhesion force function. With this as the physical basis, incipient powder consolidation, yield and cohesive steady-state flow, consolidation and compression functions, compression and preshear works are explained. As an example, the flow properties of an ultrafine limestone powder are shown. These constitutive models are used to evaluate shear cell test results for apparatus design to ensure reliable powder flow. Finally, conclusions are drawn concerning particle stressing, powder handling behavior and product quality assessment in processing industries.