On the materials and processes for additive metallurgy

该提案由两部分组成，这两部分来自于以前NSERC支持的赠款所获得的丰富经验。 该提案的第一部分是以非常规方式应用粉末冶金的创新方法。到目前为止，由粉末冶金制成的创新部件是通过合金添加制成的。然而，在需要两种不同金属的不同行为的情况下，例如可以承受乙二醇基冷却剂腐蚀的铝和非常容易受到冷却剂影响的镁，需要一种新的创新方法。类似的情况出现在3D金属打印增材制造的开发中，其中主材料可能易受循环通过部件的流体的影响，并且循环管必须由与制成部件的主合金相容并且能够承受流体的腐蚀作用的材料构造。拟议的研究是通过研究由两种不同材料制成的简单试样来解决传统粉末冶金和新兴3Dmetal增材制造的问题，并通过包括电化学在内的传统表征技术来表征它们的界面。这将导致由两种不同金属（如铝和镁）制成的较轻部件复合材料的构造，因为它们目前用于一些汽车发动机缸体。 该提案的第二部分涉及开发新型金属填充的含氟聚合物复合材料的研究，例如含有金属填料的PVDF，该金属填料由无电镀锡的铜颗粒制成，从而产生核-壳结构。新奇涉及核-壳结构的锡包覆的铜粉作为金属填料的用途。铜在加工过程中不再暴露于氧化。该复合材料将通过注射成型工艺制造，其中有机聚合物和镀锡铜粉混合，然后热压。铜芯的作用是在制造的复合材料内产生导电路径，从而增加制造的材料的导电性，而铜（芯）上的锡涂层（壳）保护铜颗粒在复合材料制造期间免受氧化。在成型过程中防止氧化是必要的，因为氧化铜表面层降低了粉末的导电性。此外，锡层扩散到相邻的铜中，产生环境稳定的金属间相。核-壳结构可以有益于许多工业应用，例如电路保护、天线、汽车和数据通信。该方案是化学镀和核-壳技术的创新组合，这两种技术都是在我们的实验室以前开发的。 因此，两个创新的方法，由传统的技术，以生产改进的产品。

This proposal consists of two parts resulting from the vast experience obtained by previous NSERC supported grants. The first part of the proposal is an innovative approach to apply powder metallurgy in an unconventional way. Until now innovative parts made by power metallurgy are made by alloying additions. However, in cases that require different behaviour by two different metals, such as aluminum which can withstand the corrosion by glycol based coolant and magnesium which is very vulnerable to coolant, a new innovative approach is needed. Similar cases arise in the development of 3Dmetal printing additive manufacturing where the main material may be vulnerable to a fluid which is circulated through the part and the circulation pipe must be constructed from a material which is compatible with the main alloy of which the part is made and can withstand the corrosion action of the fluid. The proposed research is to address the problem of traditional powder metallurgy and the emerging 3Dmetal additive manufacturing by studying simple specimens made of the two different materials and characterize their interface by traditional characterization techniques including electrochemistry. This will lead to construction of the lighter parts composites made by two dissimilar metals such as aluminum and magnesium as they presently utilized in some automotive engine blocks. The second part of this proposal relates to the research to develop a novel metallic filled fluoropolymer composite such as PVDF containing a metallic filler that is made of copper particles coated electrolessly with tin resulting in a core-shell structure. The novelty is related to the use of core-shell structured tin coated copper powders as metallic fillers. Copper is no more exposed to oxidation during processing. The composite will be fabricated by injection molding process where the organic polymer and tin coated copper powders are mixed followed by hot compression. The role of copper core is to create an electrical conduction path within the fabricated composite hence increasing the electrical conductivity of the fabricated material, whereas the tin coating (shell) on copper (core) protects the copper particles from oxidation during the composite fabrication. The protection from oxidation during the molding process is necessary because the copper oxide surface layer decreases the electrical conductivity of the powders. Additionally, the tin layer diffuses into the adjacent copper giving rise to environmentally stable inter-metallic phases. The core-shell structures can be beneficial to many industrial applications, for example circuit protection, antennas, automotive, and data communication. This proposal is the innovative combination of electroless plating and core-shell technique both developed previously in our laboratory. Thus two innovative approaches by traditional techniques to produce improved products.