Development of master alloys for improving the sintering response and mechanical properties of high performance steel components produced by powder metallurgy and additive manufacturing

开发中间合金，以改善粉末冶金和增材制造生产的高性能钢部件的烧结响应和机械性能

• 批准号: RGPIN-2018-04533
• 负责人: Blais, Carl
• 金额: $ 4.66万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=691222
• 关键词: Development; master; alloys; improving; sintering

Final density of components produced with metal powders as base material is key to achieve mechanical properties approaching those of wrought alloys. Should higher densities become reachable in an industrial context, low-cost and more sustainable production processes such as powder metallurgy or binder-jetting additive manufacturing could capture a larger volume of high-performance metallic components. The main objective of this research is to develop master alloys to promote densification of green steel compacts and optimum distribution of alloying elements through an approach based on liquid phase sintering. Interestingly, the challenges related to this objective are common to conventional powder metallurgy (PM) and binder-jetting additive manufacturing processes. Our project aims at developing master alloys with a melting temperature lower than the typical sintering temperature used for PM steels. The liquid phase that will form during sintering will serve several purposes: 1) Reduce the chemical activity of elements with high affinity for oxygen making them less sensitive to oxidation; 2) Form a liquid phase (5-8vol-%) that will wet the iron particles favouring their rearrangement in a denser stacking; 3) Show significant solubility for Fe to improve mass transport and favour neck growth through a process of dissolution-reprecipitation; 4) Accelerate spatial distribution of alloying elements within the steel matrix through liquid phase sintering; 5) Round the residual pores making them less susceptible to act as stress concentrators, crack initiation/propagation sites, etc. The master alloys will be atomized using the water atomizer available at the Powder Metallurgy Laboratory of Université Laval (LAMPOUL). Conventional PM parts as well as AM binder-jetted specimens will be pressed/printed. Studies will be carried out to determine the influence of particle size distribution, sintering profile as well as sintering atmosphere in terms of composition and dew point. Work will also be performed to model and control dimensional change as a function of the variables identified above. Finally, tensile properties as well as fatigue resistance of the most promising master alloys will be quantified. The research summarized here is directly related to 2 of the 4 main topics identified by the Metal Powder Industries Federation in its 2017 PM Industry Roadmap, namely: 1) High-density PM components and 2) Metal AM. The work briefly summarized here will foster the development of cost-effective high-density components manufactured from materials with mechanical properties comparable to wrought. Moreover, these gains will be achieved using sustainable manufacturing processes that are recognized for reducing energy consumption and production costs.

用金属粉末作为基本材料产生的成分的最终密度是实现接近世界合金的机械性能的关键。如果在工业环境中越来越高的密度，低成本和更可持续的生产过程，例如粉末冶金或固定生产的额外制造，可以捕获大量的高性能金属组件。这项研究的主要目的是开发师父合金，以通过基于液相烧结的方法来促进绿色钢契约和合金元素的最佳分布。有趣的是，与该目标相关的挑战是常规粉末冶金（PM）和绑定固定的其他制造工艺的常见。我们的项目旨在开发熔化温度低于PM钢的典型烧结温度的师资合金。在烧结期间形成的液相将有几个目的：1）减少对氧气高亲和力的化学活性，从而使其对氧化敏感； 2）形成一个液相（5-8vol-％），该液相会弄湿铁颗粒，有利于它们在浓密的堆叠中重排的铁颗粒； 3）通过溶解 - 反应过程显示了FE的重要解决方案，以改善大规模运输和有利于颈部的生长； 4）通过液相烧结加速钢基质中合金元件的空间分布； 5）围绕残留孔，使它们不易作为应力浓缩物，裂缝起始/繁殖地点等。主合金将使用在Laval大学（Lampoul）的粉末冶金实验室可用的水雾化器雾化。传统的PM零件以及AM粘合剂喷射样品将被按下/打印。将进行研究以确定粒度分布，烧结曲线以及在组成和露点方面的影响。还将进行工作以建模和控制维度变化，这是上述变量的函数。最后，将量化最有前途的主合金的拉伸性能以及抗疲劳性。此处的研究摘要与金属粉末工业联合会在2017年PM行业路线图中确定的4个主要主题中的2个直接相关，即：1）高密度PM组件和2）Metal AM。此处简要概述的工作将促进从具有与包裹相当的机械性能的材料制造的具有成本效益的高密度组件的发展。此外，使用可持续的制造工艺可以实现这些收益，这些工艺可降低能源消耗和生产成本。