Roberts R J, Rowe R C
J Pharm Pharmacol. 1985 Jun;37(6):377-84. doi: 10.1111/j.2042-7158.1985.tb03019.x.
The effect of punch velocity over the range 0.033-400 mms-1 on the compaction of a variety of materials has been studied using constants derived from the Heckel equation as criteria to describe their behaviour. For materials known to deform plastically, e.g. maize starch and polymeric materials, there was an increase in the yield pressure with punch velocity attributable to a change either from ductile to brittle behaviour or a reduction in the amount of plastic deformation due to the time dependent nature of plastic flow. For materials known to consolidate by fragmentation, e.g. magnesium and calcium carbonates, there was no change in yield pressure with increasing punch velocity. The data has been analysed in terms of the strain rate sensitivity of the materials calculated from their yield pressure at low and high punch velocities.
使用从赫克尔方程导出的常数作为描述各种材料行为的标准，研究了冲头速度在0.033-400毫米/秒范围内对这些材料压实的影响。对于已知会发生塑性变形的材料，例如玉米淀粉和聚合物材料，屈服压力会随着冲头速度的增加而升高，这归因于从韧性行为转变为脆性行为，或者由于塑性流动的时间依赖性导致塑性变形量减少。对于已知通过破碎而固结的材料，例如碳酸镁和碳酸钙，屈服压力不会随着冲头速度的增加而变化。已根据材料在低冲头速度和高冲头速度下的屈服压力计算出的应变速率敏感性对数据进行了分析。
