Co-Continuous Metal-Ceramic Interpenetrating Composites (IPCs) for Light Armour Applications

由于需要增加人员保护以及向更轻、更快、更省油的车辆发展，轻质装甲材料变得越来越重要。目前的装甲通常由许多单独的材料夹在一起组成。这可能导致制造、更换或维修复杂的重型部件。与基体金属相比，金属基复合材料（MMC）已显示出改善的强度、刚度、硬度、耐磨性和耐磨损性、较低的热膨胀系数和更好的耐高温性和抗蠕变性，同时保持足够的导电性和导热性、延展性、抗冲击性和抗氧化性，并且可能是装甲应用的理想材料。制造MMC的传统方法导致具有由分散在均匀基质金属中的离散颗粒、晶须或纤维组成的微结构的材料。这些方法在获得足够高的增强相含量方面产生问题，这由于成本增加而限制了潜在的应用，更重要的是，拉夫堡大学最近在EPSRC授权GR/S15471下的工作已经证明，可以用一定范围的铝渗透密度在理论密度的5-50%范围内的陶瓷泡沫。基于熔融金属形成互穿复合材料（IPC）。由同一研究团队开发的泡沫具有完全致密的孔壁和支柱，可提供高强度，同时孔通过窗口完全连接，使其适用于一系列应用，包括渗透。所生产的复合材料具有在所有三个维度上完全连接的陶瓷和金属相，从而产生不仅具有各向同性特性而且具有陶瓷和金属特性的真正混合的材料。这些性能可以通过改变泡沫的成分、密度和孔径来改变，通过改变截面上的泡沫密度和渗透不同的金属合金来改变。最近的初步研究表明，这些IPC具有满足装甲材料需求的潜力。它们不仅被证明具有有用的弹道性能，而且重量轻，易于制造成各种形状。现在需要做的工作是：-扩大复合材料的加工规模，以便制造全尺寸的试件。这些将有一系列的细胞大小和陶瓷含量，并将渗透两种不同的铝合金。由于许多装甲解决方案由多层系统组成，因此该技术非常适合生产完全集成的分层结构。通过将陶瓷预成型件的密度从完全致密改变为半固态，然后进行金属渗透，将可以制造两层（IPC-金属）和三层（陶瓷-IPC-金属）材料。这种类型的结构不需要将单独的材料粘合在一起，从而提高了结构的整体性能。为了充分实现这些材料的弹道应用广泛的测试是必要的。首先，基于实验室的测试将用于优化材料性能，然后由ADML和Permali进行全面的弹道测试。将在试验后对材料进行分析，以确定损坏机制、损坏区域（范围）和IPC组成的影响。将开发和测试两层和三层装甲解决方案。最后，当我们接近可以商业利用这种材料的时候，我们需要更好地理解最终用户的需求。该地区的一些公司表现出相当大的兴趣，对该项目的支持证明了这一点，他们将帮助实现这些材料的全部潜力。需要充分开展工作，以实现IPC的使用，这将在最后一项任务中解决。

Light weight armour materials are becoming increasingly important due to the need for increased personnel protection and also the move towards light, faster, more fuel efficient vehicles. Current armour usually consists of a number of individual materials sandwiched together. This can lead to heavy sections that are complex to manufacture, replace or repair. Metal Matrix Composities (MMCs) have been shown to display improved strength, stiffness, hardness, wear and abrasion resistance, lower thermal expansion coefficients and better resistance to elevated temperatures and creep compared to the matrix metal, whilst retaining adequate electrical and thermal conductivity, ductility, impact and oxidation resistance and may be an ideal material for armour applications. Traditional approaches to making MMCs, result in materials with microstructures consisting of discrete particles, whiskers or fibres dispersed in an otherwise homogeneous matrix metal. These approaches yield problems with obtaining a high enough reinforcement phase content which limits potential applications as a result of the increased costs and, more importantly, the development of anisotropic properties.Recent work at Loughborough University under EPSRC grant GR/S15471 has demonstrated that it is possible to infiltrate ceramic foams with densities in the range 5-50% of theoretical with a range of aluminium-based molten metals to form interpenetrating composites (IPCs). The foams, developed by the same research team, have fully dense pore walls and struts, which provide high strength, whilst the pores are fully connected by windows making them suitable for a range of applications, including infiltration. The composites produced have both the ceramic and metal phases fully connected in all three dimensions, yielding a material that not only has isotropic properties but a true mix of the ceramic and metal properties. These properties can be modified by varying the composition, density and pore sizes of the foams, by varying the foam density across a section and infiltrating different metal alloys.Recent preliminary has shown that these IPCs have the potential to fulfil the need for an armour material. Not only have they been shown to have useful ballistic properties but are also lightweight and easy to manufacture in a range of shapes. Work is now needed to:-Scale up the processing of the composites to allow full sized test pieces to be manufactured. These will have a range of cell sizes and ceramic contents and will be infiltrated with two different aluminium alloys.-As many armour solutions are made up of a multi-layered system, this technology is ideal for adaptation to producing a fully integrated layered structure. By varying the ceramic preform density from fully dense to semi-solid followed by metal infiltration it will be possible to manufacture two layer (IPC-metal) and three layer (ceramic-IPC-metal) materials. This type of structure negates the need to glue separate materials together, improving the overall properties of the structure.-For full realisation of these materials for ballistic applications extensive testing is needed. In the first instance, laboratory based tests will be used to optimise the material properties followed by full scale ballistic testing by both ADML and Permali. Analysis of the material following testing will be carried out to determine the damage mechanism, area (spread) of damage and the influence of IPC makeup. Two and three layer armour solutions will be developed and tested.-Finally, as we near the point where we can exploit this material commercially, we need to develop a better understanding of end users requirements. Considerable interest is being shown by a number of companies in the area, as demonstrated by the support for this project, who will assist in realising the full potential of these materials. Work is needed fully to realise the use of IPCs which will be addressed in the final task.