Novel Current-Activated Tip-based Sintering (CATS)

该奖项的研究目标是研究一种新的制造工艺，该工艺允许从粉末中控制“局部”烧结微米级和纳米级特征和器件。该工艺被称为电流激活尖端烧结（CATS），使用微米或纳米导电尖端同时向粉末床表面施加电流和受控的接触压力。控制尖端的路径以烧结/固结简单或复杂的几何形状。本研究旨在回答这个过程中的一些基本科学问题，并将通过实验和建模工作来解决。将研究工艺变量（包括电流密度、电流形式、尖端速度和粉末绿色密度/填充）对尖端下方的影响区域（工艺区）的特性和烧结行为的影响。如果成功，该方法可以用于1D，2D和3D微米和纳米级粉末制造。该工艺的优点还包括常规烧结无法达到的超快速加热和烧结速率，以及即使在纳米尺度上也应该达到的工艺区。这项研究将提供重要的见解的基本机制负责本地电流激活的“尖端为基础的”烧结行为。该方法可应用于非常广泛的材料，包括金属、金属间化合物、形状记忆合金、多孔材料和复合材料。该技术将在许多行业中具有广泛的应用，包括微/纳米传感器和致动器、微/纳米过滤器和微机电系统（MEMS）。

The research objective of this award is to investigate a novel manufacturing process that allows the controlled 'localized' sintering of micro-scale and nano-scale features and devices from powders. The process, named Current-Activated Tip-based Sintering (CATS), uses a micro or nano conductive tip to simultaneously apply electric current and controlled contacting pressure to the surface of a powder bed. The path of the tip is controlled to sinter/consolidate simple or complex geometries. The present study is designed to answer a number of fundamental scientific questions for this process and will be addressed through both experimental and modeling efforts. The influence of process variables including current density, current form, tip speed and powder green density/packing on the characteristics of the area of influence beneath the tip (process zone) and sintering behavior will be studied. If successful, the approach can be adopted for 1D, 2D and 3D micro and nano-scale powder-based fabrication. Advantages of the process also include ultra-rapid heating and sintering rates un-attainable by conventional sintering, and a process zone that should be attained even on the nano-scale. The study will offer important insights into the underlying mechanisms responsible for the localized current-activated 'tip-based' sintering behavior. The approach can be applied to a very wide range of materials, including metals, intermetallics, shape memory alloys, porous materials and composites. This technology would have wide spread applications within a number of industries, including micro/nano-sensors and actuators, micro/nano-filters and micro-electro-mechanical systems (MEMS).