Powders by design for additive manufacture through multi-scale simulations

通过多尺度模拟设计用于增材制造的粉末

• 批准号: EP/T009128/2
• 负责人: Sina Haeri
• 金额: $ 47.2万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FT009128%2F2
• 关键词: Powders; design; additive; manufacture; through

The selective laser melting process is a promising large-scale additive manufacturing (or 3D printing) technique that allows for rapid production of prototypes, and lately for weight-sensitive/multi-functional parts at small volumes, with almost arbitrary complexity. The process builds the final parts layer-upon-layer by going through three main stages during each cycle: (1) deposition of a layer of fine powder (with a typical grain size of approximately 0.03 mm) on a fabrication surface to form a thin bed of powder, which is only marginally thicker than the average grain size; (2) a laser beam then melts the powder bed at specific locations, based on a 3D computer model of the final product; (3) the powder grains then fuse at those locations after cooling and solidifying to produce a layer of the final product.In general, the selective laser melting process and additive manufacturing provide several advantages compared to conventional manufacturing techniques, such as greater design freedom, mass customisation and personalisation of products, production of complex geometries to improve performance and reduce labour costs, decreased wastage of precious materials, and new business models and supply chains. However, several challenges also exist. For example, a lack of understanding of the impact of powder grain shape on the underlying physical processes has forced the industry to require the majority of individual powder grains to be spherical. Such a stringent requirement increases the cost of powder (raw material), which consequently increases the production cost and hinders the development of new processes and the introduction of new materials. To address this issue, high-quality research software for process simulation is required to complement experiments and to enable new scientific discoveries and innovations. The present research programme addresses this technological need by providing a novel computational package capable of modelling various complex physical phenomena underlying the selective laser melting process. To achieve this, high-performance computing will be used to track the motion of individual grains in the system, their interaction with a laser beam, and their phase changes. This computational package will then be used to uncover the complex impact of powder grain shapes on the absorption and scattering of a laser beam within the bed and the following rapid melting process. Furthermore, it is hypothesised that elongated or satellite-spherical particles with small inclusions on their surfaces (grain shapes which are commonly present in powders and are generally considered undesirable) can, in fact, improve the process if their number densities are carefully selected. This hypothesis will be tested here for the first time, which can greatly reduce the cost of raw materials for selective laser melting, which results in wider adoption of this enabling technology.

选择性激光熔化工艺是一种很有前途的大规模增材制造（或 3D 打印）技术，可快速生产原型，最近还可以生产小批量、几乎任意复杂性的重量敏感/多功能零件。该工艺在每个循环中经过三个主要阶段，逐层构建最终零件：(1) 在制造表面上沉积一层细粉末（典型晶粒尺寸约为 0.03 毫米），形成薄薄的粉末层。粉末床，仅比平均粒度稍厚； (2) 然后，根据最终产品的 3D 计算机模型，激光束在特定位置熔化粉末床； (3) 粉末颗粒在冷却和凝固后在这些位置融合，产生一层最终产品。一般来说，选择性激光熔化工艺和增材制造与传统制造技术相比具有多种优势，例如更大的设计自由度，产品的大规模定制和个性化、生产复杂的几何形状以提高性能并降低劳动力成本、减少贵重材料的浪费以及新的商业模式和供应链。然而，也存在一些挑战。例如，由于缺乏对粉末颗粒形状对潜在物理过程的影响的了解，迫使该行业要求大多数单个粉末颗粒为球形。如此严格的要求增加了粉末（原材料）的成本，从而增加了生产成本并阻碍了新工艺的开发和新材料的引入。为了解决这个问题，需要高质量的过程模拟研究软件来补充实验并实现新的科学发现和创新。目前的研究计划通过提供一种新颖的计算包来满足这一技术需求，该计算包能够对选择性激光熔化过程背后的各种复杂物理现象进行建模。为了实现这一目标，高性能计算将用于跟踪系统中单个颗粒的运动、它们与激光束的相互作用以及它们的相变。然后，该计算包将用于揭示粉末颗粒形状对床内激光束的吸收和散射以及随后的快速熔化过程的复杂影响。此外，假设表面上有小夹杂物的细长或卫星球形颗粒（粉末中常见的颗粒形状通常被认为是不理想的）如果仔细选择它们的数密度，实际上可以改进该过程。这一假设将在这里首次得到检验，这可以大大降低选择性激光熔化的原材料成本，从而导致这种使能技术得到更广泛的采用。

项目成果

Lees-Edwards boundary conditions for the multi-sphere discrete element method

多球离散元法的 Lees-Edwards 边界条件

• DOI: 10.1016/j.powtec.2021.05.025
• 发表时间: 2021-09-01
• 期刊: Powder Technology
• 影响因子: 5.2
• 作者: Nathan Berry;Yonghao Zhang;S. Haeri
• 通讯作者: S. Haeri

Analysis of radiation pressure and aerodynamic forces acting on powder grains in powder-based additive manufacturing

粉末增材制造中作用于粉末颗粒的辐射压力和气动力分析

• DOI: http://dx.10.1016/j.powtec.2020.04.031
• 发表时间: 2020
• 期刊: Powder Technology
• 影响因子: 5.2
• 作者: Haeri S

Contact models for the multi-sphere discrete element method

多球离散元法的接触模型

• DOI: http://dx.10.1016/j.powtec.2022.118209
• 发表时间: 2023
• 期刊: Powder Technology
• 影响因子: 5.2
• 作者: Berry N

The effects of interstitial inert gas on the spreading of Inconel 718 in powder bed fusion

间隙惰性气体对 Inconel 718 粉床熔融铺展的影响

• DOI: http://dx.10.1016/j.addma.2023.103737
• 发表时间: 2023
• 期刊: Additive Manufacturing
• 影响因子: 11
• 作者: Khajepor S