加拿大École de technologie supérieure的Vladimir Brailovski团队通过两种不同雾化技术(即等离子体雾化和气体雾化)生产三批Ti-6Al-4V粉末,并对其进行粒度和流动性的表征,不同层厚度和构建方向的测试样本进行3D打印和后处理,从而建立粉末特性与最终产品在几何和机械性能之间的相关性。这项研究表明,使用具有有限数量细颗粒的高度球形粉末可提高其流动性,并获得具有改善的机械和几何特性的LPBF组件。
ABSTRACT: This is a study of the flow properties of a range of magnetic toners produced from a common base in relation to three physical variables – the milling method, the type and amount of flow additive and to a limited extent, particle size.Two methods of milling were used for sample preparation – air jet milling and mechanical milling. The flow additives were either HMDS or PDMS silicas.The study used the FT3 powder Rheometer (Freeman Technology) to determine the rheology of powder samples in terms of the energy required to cause a powder to flow.The dependence upon environmental factors commonly imposed on powders such as flow rate, the level of aeration and the amount of consolidation are determined for each of the materials. The propensity to retain air is also investigated and quantified. The results clearly indicate the complex nature of toners and how their flow properties are affected by a large number of variables, of which one of the most significant is the effect of aeration and de-aeration representing the transition from fluidisation to consolidation.