Cold spray is on the way to becoming a mainstream technology for coating and additive manufacturing processes. While there have been many advances in various aspects of this technology, the question of tailoring the ‘ideal’ feedstock powder for cold spraying has remained open. In particular, the mechanical strength and its dependence on the particle size, which are amongst the most relevant properties of the feedstock powder for cold spraying, are rarely covered when reporting powder specifications. This is mainly because of the lack of standardised methods of characterisation for these specific properties. In the present case study, we demonstrate how compression tests of single Inconel 718 particles by using a modified nanoindenter can address this central question. Data analyses are supported by finite element modelling of particle compression for a range of plastic behaviours. The results of simulation are then stored in the form of a surrogate model for subsequent comparison with the experimental data. Thus, the ultimate tensile strength and the size of the examined particles are calculated directly from the measured force-displacement data. The paper will also discuss how this information can be used to optimise cold spraying, and so, unveils a key step towards the design and manufacturing of cold-spray-specific feedstock powder.

中文翻译：

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颗粒压缩测试：定制冷喷涂原料粉末的关键步骤

冷喷涂正在成为涂料和增材制造工艺的主流技术。尽管该技术的各个方面都有许多进步，但为冷喷涂量身定制“理想”原料粉末的问题仍然悬而未决。特别是，在报告粉末规格时，很少涉及机械强度及其对粒度的依赖性，这是用于冷喷涂的原料粉末最相关的特性之一。这主要是因为缺乏针对这些特定属性的标准化表征方法。在本案例研究中，我们演示了使用改良的纳米压头对单个Inconel 718颗粒进行的压缩测试如何解决这个核心问题。数据分析得到了一系列塑料行为的颗粒压缩的有限元建模的支持。然后将模拟结果以替代模型的形式存储，以便随后与实验数据进行比较。因此，直接从测得的力-位移数据中计算出极限抗拉强度和所检查颗粒的尺寸。本文还将讨论如何将这些信息用于优化冷喷涂，因此，揭开了设计和制造特定于冷喷涂原料粉末的关键一步。直接从测得的力-位移数据计算出极限抗拉强度和被测颗粒的尺寸。本文还将讨论如何将这些信息用于优化冷喷涂，因此，揭开了设计和制造特定于冷喷涂原料粉末的关键一步。直接从测得的力-位移数据计算出极限抗拉强度和被测颗粒的尺寸。本文还将讨论如何将这些信息用于优化冷喷涂，因此，揭开了设计和制造特定于冷喷涂原料粉末的关键一步。