Light-Weight Matrix Materials Based on Mg-Intermetallic Alloys

在当前和未来的商业和军事系统中，对更高材料性能的长期需求要求材料性能的改进。高熔点、低密度和高强度是实现未来系统性能目标所必需的材料特性。使用传统的金属合金(包括熔化温度仅为660摄氏度的铝基合金)不再能满足这些要求。镁基金属间化合物是满足上述要求的最佳候选者之一。基于密度、熔点(926℃)、晶体结构(B2)和抗氧化性的考虑，金属间化合物mGy在500℃-550℃的应用中具有巨大的潜力作为一种轻质材料。第一阶段的研究集中于建立金属间化合物的室温和高温力学性能，提高金属间化合物的室温延展性、断裂韧性和高温强度。第一阶段的研究应该确定弥散增强的mGy射线在第二阶段计划下进一步发展的潜力。独特的等离子体合成工艺将被用来生产比强度高于迄今报道的金属间化合物镁合金。高强度比镁金属间化合物合金在航空航天和交通运输等领域有着很高的应用需求。此外，基于这种金属间化合物的纤维增强复合材料表现出非常高的特性。

Chronic needs for higher materials performance in present and future commercial and military systems mandate improvements in materials properties. High melting point, low density and high strength are among the material properties necessary to achieve future system performance goals. Such requirements can no longer be met using conventional metal alloys (including aluminum-based alloys which melt at only 660 C). Magnesium-based intermetallics are among the best candidates to fulfill the aforementioned requirements. Based on density, melting point (926 C), crystal structure (B2), and oxidation resistance considerations, an intermetallic compound MgY has significant potential as a light- weight material for 500 C - 550 C applications. The Phase I investigation concentrates on establishing the room and high temperature mechanical properties of the intermetallic MgY, improving the room temperature ductility, fracture toughness and elevated temperature strength of the intermetallic. The Phase I investigation should establish the potential of dispersion- strengthened MgY for further development under a Phase II program. Unique plasma synthesis processing will be utilized to produce these magnesium intermetallic alloys with specific strengths higher than heretofore reported. High strength-to-weight ratio magnesium intermetallic alloys have a high demand in aerospace and transportation applications. Further, fiber-reinforced composites based on such intermetallic matrices exhibit very high specific properties.