Modelling of Resonant Acoustic Mixing Parameters

传统上，多材料共混部件在行星式混合器中混合，铸造成块/坯，并经历减材加工以形成成形部件。合成材料和高填充树脂基系统等复合材料在转鼓和其他传统的叶片式混合机中长时间混合，倾析，模塑成块，并再次进行减材加工。共振声混合（RAM）是一种新型的粉末/粉末、粉末/流体和流体/流体混合技术，它可以直接将材料混合成最终的净（或近净）部件形状，而无需进一步处理，去除或显著减少材料浪费、时间和危险。RAM正在与一家国防承包商进行试验，迄今为止显示出良好的效果。然而，这种混合技术的建模仍处于起步阶段，尚未得到解决，因此不能说是优化的。许多混合（强度、时间、压力温度）、材料（颗粒大小、形状、预混合、添加顺序）和工具（形状、成分、混合顶部空间）参数影响RAM的效率，因此如果建模，将在优化混合过程中增加重要价值。建模和/或试验将提高对能力的理解，包括限制和机会。可以识别混合最佳点的相空间，通过避免刀口场景进一步降低潜在处理操作的风险。一旦混合，粉末的混合物仍然需要倒入模具中。这提供了一个更可控的流动环境，但可能导致相分离、分层和其他形式的去混合，特别是考虑到不同尺寸或密度的颗粒时。

Traditionally, multi-material blended components are mixed inplanetary mixers, cast to blocks/blanks, and undergo subtractivemachining to form shaped components. Composites such assyntactics and highly filled resin based systems are blended in rotarydrums and other conventional blade based mixers over long periodsof time, decanted, moulded to blocks and again undergo subtractivemachining. These are both time consuming, wasteful and potentiallyhazardous when working with energetically-sensitive materials.Resonant Acoustic Mixing (RAM) is a novel powder/powder,powder/fluid and fluid/fluid mixing technology that has the potentialto directly mix materials into the final net (or near net) componentshape without further processing, removing or significantly reducingmaterial waste, time and hazards. RAM is being trialled with adefence contractor and is showing excellent results to-date. However,modelling of this mixing technique is in its infancy and has not beenaddressed and thus, cannot be said to be optimised. Numerous mixing(intensity, time, pressure temperature), material (particle size, shape,pre-blending, order of addition) and tooling (shape, composition,mixing head space) parameters impact the efficiency of RAM andthus if modelled would add significant value in optimising the mixingprocess.Modelling and/or trials would improve understanding of thecapability, both limitations and opportunities. A phase space ofmixing sweet-spots could be identified, further de-risking potentialprocessing operations by avoiding knife-edge scenarios. Once mixed,the blend of powders still needs to be decanted to a mouldtool. Thispresents a more controlled flowing environment but can lead to phaseseparation layering and other forms of de mixing especially when considering particles of different size or density.