Development of Innovative Aluminum Powder Metallurgy (PM) Alloys Utilizing Hybrid Alloying Technology

利用混合合金技术开发创新型铝粉末冶金 (PM) 合金

• 批准号: 250034-2013
• 负责人: Bishop, Donald
• 金额: $ 2.11万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=645531
• 关键词: Development; Innovative; Aluminum; Powder; Metallurgy

The focus of this proposal is aluminum powder metallurgy (PM) processing. This is an emerging near-net-shape metal forming technology wherein aluminum-based powders (and powdered forms of the desired alloying additions) are directly manipulated into geometrically complex components through a sequence of powder compaction, liquid phase sintering, and secondary operations such as heat treatment. Aluminum PM has advanced steadily in recent years principally through the development of new alloys that exhibit a high sintered density (>99%) and in turn, significant improvements in ambient mechanical properties relative to the out dated conventional blends now in use for over 40 years. While the next generation materials open many new applications for aluminum PM processing, new challenges have arisen as well. The most prolific is their propensity for non-uniform shrinkage during sintering. Coming as a result of the intense densification behaviour, it yields distorted sintered products and greatly diminishes the near-net-shape advantage upon which aluminum PM is built. To mitigate the distortion dilemma, the applicant recently designed a concept deemed "hybrid alloying" whereby the sintering particles of aluminum would be strengthened by the addition of a small amount of prealloyed zirconium. This element has a slow diffusion rate in aluminum and forms a refined distribution of Al3Zr particles that are hard, exceptionally fine ((<20nm), thermodynamically stable, and highly resistant to thermal coarsening - attributes that enable the aluminide particles to act as efficient strengthening features throughout the complete sintering cycle. Research on the concept has been restricted to a single base alloy and dilute concentrations of Zr to date yet the results are highly promising and imply that a much broader scope of opportunities exists for the technique. Thus, the objective of this proposal is to expand research on hybrid alloying to maximize the likelihood of widespread commercial adaptation. Activities will address an enhanced fundamental understanding, chemical refinements, the use of hybrid alloying in an array of alloys, and mechanical testing.

本提案的重点是铝粉冶金（PM）加工。这是一种新兴的近净形状金属成形技术，其中铝基粉末（以及所需合金添加剂的粉末形式）通过一系列粉末压实、液相烧结和二次操作（如热处理）直接被操纵成几何复杂的部件。铝PM近年来稳步发展，主要是通过开发具有高烧结密度（>99%）的新合金，反过来，相对于已经使用了40多年的过时的传统混合物，环境机械性能有了显着改善。虽然下一代材料为铝粉末冶金加工开辟了许多新的应用，但也出现了新的挑战。最多产的是它们在烧结时不均匀收缩的倾向。由于强烈的致密化行为，它产生扭曲的烧结产品，并大大降低了铝粉末冶金的近净形状优势。为了缓解扭曲困境，申请人最近设计了一种被称为“混合合金化”的概念，即通过添加少量预合金化锆来增强铝的烧结颗粒。这种元素在铝中的扩散速度很慢，形成了一种精细分布的Al3Zr颗粒，这些颗粒坚硬、非常细（<20nm）、热力学稳定、高度耐热粗化——这些属性使铝化物颗粒在整个烧结循环中都能起到有效的强化作用。迄今为止，对该概念的研究仅限于单一基合金和稀Zr浓度，但结果非常有希望，并意味着该技术存在更广泛的机会范围。因此，本提案的目标是扩大对混合合金的研究，以最大限度地提高广泛商业适应的可能性。活动将涉及加强基本理解，化学精炼，在一系列合金中使用混合合金，以及机械测试。