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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=753946
• 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.

以金属粉末为基础材料生产的部件的最终密度是实现接近锻造合金机械性能的关键，如果在工业环境中能够达到更高的密度，则需要采用粉末冶金或粘合剂喷射添加剂等低成本且更可持续的生产工艺。这项研究的主要目标是开发中间合金，通过基于液相的方法促进绿色钢坯的致密化和合金元素的最佳分布。匿名烧结，与此目标相关的挑战对于传统粉末冶金 (PM) 和粘合剂喷射增材制造工艺来说是常见的，我们的项目旨在开发熔化温度低于粉末冶金液相典型烧结温度的中间合金。烧结过程中形成的氧化物有多种用途： 1) 降低对氧具有高亲和力的元素的化学活性，使其对氧化不太敏感 2) 形成液相（5-8vol-%）；这将润湿铁颗粒，有利于其在更密集的堆积中重新排列；3）显示出显着的铁溶解度，以通过溶解-再沉淀过程改善传质并有利于颈部生长；4）通过以下方式加速合金元素在钢基体内的空间分布； 5) 使残余孔隙变圆，使其不易成为应力集中点、裂纹萌生/扩展点等。母合金将用水雾化拉瓦尔大学粉末冶金实验室（LAMPOUL）提供的雾化器将进行压制/打印传统粉末冶金零件以及增材制造粘合剂喷射样品的研究，以确定颗粒尺寸分布、烧结轮廓以及的影响。还将对烧结气氛的成分和露点进行建模并控制尺寸变化作为上述变量的函数。最有前途的母合金将被量化。这里总结的研究与金属粉末工业联合会在其 2017 年粉末冶金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) 高密度粉末冶金成分和 2) 金属。此处简要概述的工作将促进由具有与锻造相当的机械性能的材料制造的具有成本效益的高密度部件的发展，并且这些成果将通过使用被认为可以减少能源的可持续制造工艺来实现。消耗和生产成本。